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HUMAN 

AN ATOM Y 

PHYSIOLOGY 

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H YG1ENE 




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Forms and Formulas of Analysis, Syntactical Reso- 
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BROWN'S GRAMMARS. 

The Standard Authority in the Correct Use of the 
ENGLISH LANGUAGE. 

The School Series comprises: 

BROWN'S LANGUAGE LESSONS, 

170 pages. 

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156 pages. 

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A VALUABLE BOOK OF REFERENCE. 

THE GRAMMAR OF 

ENGLISH GRAMMARS, 

With an Introduction, Historical and ^ Critical , 

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Tenth Edition— Revised and Improved. 
WILLIAM WOOD & COMPANY, Publishers, 

43, 45 and 47 East Tenth Street, New York. 



HUMAN 
ANATOMY PHYSIOLOGY 

AND 

HYGIENE 



WITH SPECIAL REFERENCE TO THE EFFECTS 
OF STIMULANTS AND NARCOTICS 



FOR USE IN PRIMARY AND INTERMEDIATE SCHOOLS 



CHARLES H. MAY, M.D. 

Chief-of-Eye- Clinic and Instructor in Ophthalmology, Vanderbilt Clinic, College of 
Physicians ana Surgeons, Medical Dept., Columbia College, N. T.; Professor of 
Diseases of the Eye ana Ear, College of Physicians and Surgeons, 
; Asst. Surgeon, New TorJc Ophthalmic and Aural Insti- 
tute ; Asst. Oculist, Mt. Sinai Hospital, N. Y.; Fellow of 
the New TorJc Academy of Medicine, etc., etc. 



THIRD EDITION 



ILLUSTRATIONS PRINTED IN COLO 



WILLIAM WOOD AND COMPANY 
NEW YORK 




HH 



Th-y 1 



a, 



COPYKIGHT, 1889 AND 1893, BY 

WILLIAM WOOD & COMPANY. 



PREFACE. 



In the following pages the author has endeavored to pre- 
sent, in as simple and clear a manner as possible, the most im- 
portant facts relating to the anatomy, physiology, and hygiene 
of the human bod}'. 

Of late years physicians have laid great stress upon the 
study of the prevention of disease ; and, keeping pace with 
this improvement, the laity have become better informed about 
matters pertaining to the care of the body than formerly. The 
great utility of such knowledge has led to the enactment of 
laws in New York and other States making provision for the 
study of physiology and hygiene in the public schools, with 
special reference to the effects of stimulants and narcotics upon 
the human system. Such legislative provisions are very grati- 
fying. Proper instruction to children on these subjects must 
do much to diminish the amount of sickness and raise the 
general standard of health. 

The author has endeavored to use the simplest terms com- 
patible with clearness. A certain number of technical terms 
are unavoidable ; these are defined in the glossary at the end 
of the volume. 

The lessons will be made more interesting and valuable if 
illustrated by the various tissues obtainable at the butchers' ; 
thus, the heart of a calf will serve nicely to show the general 
shape and arrangement of cavities and valves in the human 



4 PREFACE. 

heart. In the same way other organs and tissues should be 
utilized by the teacher to elucidate the various parts of the 
body. The skeleton and its different parts should be before 
the class in reciting upon the bones. 

In the description of the effects of stimulants and narcotics 
upon the human body, only such statements have been made 
as can be found in the works of standard authors on these 
subjects. It is not necessary to deviate from the truth in order 
to impress children with the great amount of bodily harm and 
misery which the extensive indulgence in stimulants and nar- 
cotics causes. 

The synopsis given at the end of each chapter is intended to 
be of use in reviews and in guiding the teacher in a systematic 
presentation of the subject. 

CHARLES H. MAY, M.D. 



THIRD EDITION. 



The exhaustion of the second edition has enabled the author 
to make desirable changes and additions. It has also been 
thought advisable to devote a separate chapter to the con- 
sideration of the effects of stimulants and narcotics. 

C. H. M. 
692 Madison Avenue, New York, Oct. 1, 1893. 



CONTENTS. 



CHAPTEK I. 
Introduction. 



The Human Body the Highest Form of Living Being — What Hygiene 
Treats of — What Anatomy Teaches Us — What we Learn by the Study 
of Physiology — Differences in Meaning of Terms Anatomy, Physiol- 
ogy, and Hygiene — Different Forms of Animal Life — Life in Plants 
— Differences between Plants and Animals — Organs — Functions — 
Subdivisions of the Body — Tissues— Further Subdivisions, the Cell, 
the Fibre— Parts of the Body— The Head and Neck— The Trunk — 
The Upper Limbs — The Fingers— The Lower Limbs — Synopsis of 
Introduction — Questions on Introduction. , 13 

CHAPTER II. 

The Framework: or Skeleton. 

Position in the Higher Animals — Uses of Bones : Support, Protection, 
Strength, Motion — Number of Bones — Forms of Bones : Long, Short, 
Flat, Irregular — Structure of Bone : Surface, Interior, Periosteum, 
Spaces, Color — Composition of Bone — -Variations in Composition in 
Early and in Advanced Life— Care of the Skeleton : Effects of Faulty 
Position, Tight Clothing, Improperly-shaped Shoes, Stimulants and 
Narcotics, Poor Health — Fracture of a Bone — Parts of the Skeleton : 
Head, Trunk, Upper and Lower Limbs — Bones of the Head : Cranium 
and Face — The Cranium : Frontal, Parietal, Occipital, Temporal, etc. ; 
Ragged Edges — The Face : Orbits ; Nose ; Nasal and Malar Bones; 
Upper and Lower Jaws— Mobility of the Skull— Bones of the Trunk 
— The Spinal Column ; Sacrum and Coccyx ; Canal for Spinal Cord 
—The Pelvis — The Hip-Bone — The Collar-Bone — The Shoulder- 



CONTENTS. 

Blade— The Breast Bone— The Ribs: True, False, Floating — The 
Chest : Boundaries ; the Diaphragm — The Bones of Upper Limb — 
The Humerus — The Bones of the Forearm; Radius, Ulna — The 
Bones of the Wrist and Hand : the Wrist, the Palm, the Fingers— 
The Bones of the Lower Limb— The Femur — The Patella— The 
Bones of the Leg : Tibia, Fibula— The Bones of the Foot : the Heel, 
Instep, Toes — Synopsis of Skeleton — Questions on the Skeleton. 21 



CHAPTER III. 

The Joints. 

Definition — Uses — Subdivision — Immovable Joints — Sutures — Slightly- 
Movable Joints : General Arrangement, Ligaments, Varieties : Glid- 
ing, Hinge, Pivot, Ball-and- Socket — Accidents to Joints — Synopsis 
of Joints — Questions on the Joints 41 



CHAPTER IV. 

The Muscles and Motion. 

Function of Muscles — Description of Muscle tissue — Tendons — Fat- 
Uses of Fat : Warmth, Protection, Food, Appearance — Kinds of 
Muscle-tissue — Voluntary Muscles — Involuntary Muscles — Mixed 
Muscles — How Muscles Act — Influence of the Brain and Nerves — 
Ordinary Muscular Movements very Complex — Groups of Muscles — 
Facial Expressions — Number of Muscles — Shape of Muscles— Size of 
Muscles— A Few Important Muscles : Biceps, Triceps, Pectoralis, 
Diaphragm— Tendon of Achilles— The Care of Muscles— Exercise : 
Necessity, Amount, Kind, Proper and Improper — Effects of Alcohol 
and Tobacco on Muscles— Changes in Muscle by Use of Alcohol- 
Synopsis of Muscles and Motion— Questions on Muscles and Mo- 
tion 47 



CHAPTER V. 

Food and Drink. 

Necessity for Food and Drink — Essential to Life— Difference in Food of 
Plants and of Animals — Difference in the Food of Different Animals 
— Carnivorous Animals— Herbivorous Animals— Different Kinds of 



CONTENTS. 7 

Food Required by Man — Fleshy Food — Vegetable Food— Starch- 
Green Vegetables — Fat and Fatty Food — Water — -Tea and Coffee — 
Necessity for Combination of all Forms of Food and "Water— Some 
of the Simplest Forms of Food — Meat and Fish — Bread — Milk : 
Cream, Butter, Cheese— Eggs — Variety in Food — Proper Food — Meth- 
ods of Cooking: Boiling, Stewing, Frying, Broiling, Roasting, Baking 
— Cautions Regarding Eating — Drinking-water — Dangers of Well- 
water — How Poisoning Occurs — How Avoided — Synopsis of Food 
and Drink — Questions on Food and Drink 63 



CHAPTER VI. 

Digestion. 

Definition — The Various Organs of Digestion — Alimentary Canal — The 
Mouth — Teeth : Temporary, Permanent — Parts of Teeth — Structure 
of Teeth— Names of Teeth— Care of the Teeth— The Salivary Glands : 
Parotid, Sublingual, Submaxillary — Saliva — Effects of Chewing Gum 
—The Throat— The Tongue— The Gullet— The Stomach: Descrip- 
tion, Pylorus, Coats— Gastric Juice — Gastric Tubules — Pepsin — 
Function of Gastric Juice — Uses of Stomach : Digestion, Storehouse, 
Pulverizer — Stomachs in Certain Lower Animals — Effect of Tobacco 
on Stomach — Effect of Alcohol on Stomach — Discovery of How the 
Stomach Acts — "Heavy" and "Light" Food— The Bowels: Sub- 
divisions, Pylorus, Duodenum, Small Intestine, Large Intestine, At- 
tachment to Backbone, Coats— The Peritoneum — Motion of Intes- 
tines—Projections on Inner Surface of Intestines — The Work of the 
Intestines : Digestion— Starchy, Fatty, Fleshy Food — Openings into 
Small Intestines: From Pancreas, From Liver — The Liver and 
Gall-bladder : Position, Description— Uses of the Liver : Bile, Puri- 
fy Blood, Remove Impurities — Liver Cells— Bile — Action of Bile — 
Purification of Blood by Liver — The Liver as a Storehouse for 
Nourishment — The Unhealthy Liver : Gout— The Drunkard's Liver 
— The Pancreas : Pancreatic Juice — Uses of Pancreatic Juice — 
Absorption — Method of Absorption by Blood vessels — Lacteals — 
Habits which are Injurious to Proper Digestion : Eating too 
Quickly, Eating too Much, Eating too Many Sweets and Sours, 
Chewing Gum, Ice-water in Large Quantity, Violent Exercise after 
Meals, Severe Brain-work after Meals, Bathing after Meals, Excite- 



CONTENTS. 

meat, Alcoholic Drink, Smoking- — The Spleen : Description, Posi- 
tion, Use, Enlargement— Synopsis of Digestion — Questions on Diges- 
tion 74 



CHAPTER VII. 

The Blood and the Circulation— The Heart and the Blood- 
vessels. 

Importance of the Blood — Appearance of the Blood, Color — Composition 
of the Blood: Fluid, Globules— Blood-globules : Number — Micro- 
scope — Red Blood-globules — White Blood-globules — The Plasma — 
The Blood of Other Animals — Use of the Red Blood globules — Use 
of the Plasma— Difference between the Blood in Arteries and the 
Blood in Veins — Clotting of the Blood — Value of the Clotting of 
Blood — The Circulation : How Seen in the Frog — The Heart — Situa- 
tion of the Heart — Form of the Heart — The Pericardium— Cavities 
of the Heart, Grooves, Auricles, Ventricles — Function of the Heart- 
Frequency of the Heart-beats— Course of the Blood — Circulation 
through the Lungs — Changes in the Blood while Passing through the 
Lungs and through the System : The Aorta — Valves of the Heart — 
The Blood-vessels : Arteries, Veins, Capillaries — The Arteries — 
The Pulse — The Capillaries — The Veins : Differences between Veins 
and Arteries — Valves of the Veins— Rapidity of the Circulation of 
the Blood — Fainting: Its Treatment— Bleeding : Its Treatment, 
Hemorrhage — How to Have a Good Circulation — Exercise — Effects 
of Alcohol upon the Heart and the Circulation — Effect of Alco- 
hol upon the Arteries ; Apoplexy — Effects of Tobacco upon the 
Heart and Circulation, "Tobacco Heart" — The Lymphatics, Differ- 
ence between them and Arteries, Use, Course ; Lacteals — Synopsis 
of the Blood and the Circulation, the Heart and the Blood-vessels — 
Questions on Chapter VII. . , 100 



CHAPTER VIII. 

The Organs op Voice and Breathing. 

Definitions— Course of the Inspired Air— The Organ of Voice— The Lar- 
ynx — Form and Situation — Parts of Larynx— Triangular and Circular 
Pieces — The Epiglottis — The Vocal Cords — Their Protection of the 



CONTENTS. 9 

Windpipe — The Vocal Cords in Breathing — How Sounds are Pro- 
duced — The Varieties of Vocal Sounds — Speaking — The Trachea or 
Windpipe — Situation and Form — The Air-passage and the Food- 
passage — Eings of the Windpipe— Branching of the Windpipe — The 
Bronchi — The Lungs — Division and Situation — Shape of the Lungs 
— Structure of the Lungs — Subdivision of the Bronchi — The Air- 
vesicles — The Pleura — Breathing is Involuntary — Movements of the 
Chest in Breathing — Mouth-breathing — Frequency of Breathing — 
Changes which Breathing Produces in the Blood and Tissues — 
Changes Produced in the Air by Breathing — The Poisonous Gases — 
Effects of Impure Air — Purification of the Air — How Plants Live and 
Grow — Ventilation — Simple Means of Ventilating — Absence of 
Draughts — Necessity for Sunlight — Effect of Tight Clothing upon 
Breathing — The Deformed Chest — Effects of Tobacco Smoke upon 
the Lungs and Throat — Synopsis of Organs of Voice and Respiration 
— Questions on Organs of Voice and Respiration 125 

CHAPTEE IX. 

The Heat of the Body. 

Our Body may be Compared to a Stove — Fuel — Combustion — Work, the 
Result of the Combustion of Fuel — Refuse, another Result of the 
Burning of Fuel — The Results of the Combustion of Food— Casting 
off the Refuse Materials from the Body— Food and Oxygen Produce 
Heat and Work — Warm-blooded and Cold-blooded Animals — Heat of 
the Human Body in Health — Heat of the Human Body at the Sur- 
face — Heat of the Body in Sickness — Regulation of the Bodily Heat 
— Warm Clothing — How to Keep Warm in Winter — How to Keep 
Cool in Summer — How the Body is Kept Cool in Summer — Effects of 
the Passage of Moisture into the Air — Perspiration — Ice-water in 
Summer — Sunstroke — Effects of Cold — Synopsis of the Heat of the 
Body — Questions on the Heat of the Body 143 

CHAPTEE X. 

The Nervous System. 

Parts of the System already Described— Functions Existing in both Ani- 
mals and Plants — Similarity in the Structure of Plants and Animals 
— Absence of Nervous System in Plants — Most Perfect Nervous Sys- 



10 CONTENTS. 

tern in Man — Function of the Nervous System— Subdivisions of the 
Nervous System — Brain — Spinal Cord — Nerves — Examples of the 
Action of the Nervous System — Rapidity of Action of the Nervous 
System — Coverings of the Brain— Size ' and Weight of the Brain 
— Divisions of the Brain : Cerebrum, Cerebellum, Medulla — The 
Cerebrum— Gray and White Parts of the Cerebrum — The Cere- 
bellum—The Medulla — The Cranial Nerves : Twelve Sets— Functions 
of the Brain — Mind, Will, Thought, Memory, Intelligence — The 
Work of the Brain — Reason and Judgment — Intelligence — Training 
the Brain— The Spinal Cord — Interior of the Spinal Cord — The 
Spinal Nerves— Kinds of Nerves: Sensation and Motion — Functions 
of the Spinal Cord — Reflex Action — Examples of Reflex Action — 
Sleep— Amount of Sleep— Sleep of Children— Uses of Sleep— Time 
for Sleep— Nervousness— Wakefulness— Effects of Alcohol upon the 
Nervous System — Delirium Tremens — Effects of Tobacco upon the 
Nervous System — Effects of Coffee and Tea upon the Nervous Sys- 
tem — The Sympathetic System of Nerves— Synopsis of the Nervous 
System — Questions on the Nervous System 154 



CHAPTER XI. 

The Senses. 
Definition — Enumeration — Special Senses. 

The Sense of Touch and the Skin — Thickness — Uses of Skin — Protection 
— The Skin as the Organ of Sensation — Throwing off Water, Salts, 
and Poisonous Matters — Regulating the Bodily Warmth — Structure 
of the Skin — Scarf-skin — True Skin — Color cf the Skin — Markings of 
Skin — Attachments of Skin — The Perspiration tubes — The Pores — ■ 
Perspiration — Sensible and Insensible Perspiration — Uses of the Per- 
spiration—The Oil-tubes — The Hair— The Nails— Care of the Skin 
— The Results of Uncleanliness and Filth- Bathing— Warm Baths — 
Cold Baths— Turkish and Russian Baths — Clothing— Exercise— Cos- 
metics— Care of the Hair — Care of the Nails — Synopsis of Sense of 
Touch and the Skin — Questions on the Sense of Touch and the 
Skin 175 

The Nose and the Sense of Smell— Functions of Nose — Breathing Channel 
and Smelling Channel— Parts of the Nose — Nerves of Smell — Sense 
of Smell in Lower Animals — Cold in the Head — Use of Smell— Sweet 



CONTENTS. 11 

Scents — Synopsis of Nose and Sense of Smell — Questions on Nose 
and Sense of Smell 186 

The Tongue and the Sense of 1 Ytste— Structure of Tongue — Uses of Tongue 
— Uses of Sense of Taste — Abuse of Sense of Taste — Synopsis of 
Tongue and Sense of Taste — Questions on Tongue and Sense of 
Taste 190 

The Eye and the Sense of Sight — Protections to the Eye — The Eyelids — 
The Eyebrows and Eyelashes — Parts of the Eye — Interior of the Eye 
— The Iris — The Muscles of the Eye — How we See — Resemblance of 
the Eye to the Photographer's Camera— The Nerves of the Eye — 
Blindness — Images — The Tears— Care of the Eyes : Rest for the Eyes, 
Fine Print, Direction of the Light, Reading while Lying Down, 
Reading in the Cars, Contagious Eye Disease, Stooping in Reading — ■ 
Weak Sight— Old Sight— Synopsis of Eye and Sense of Sight — 
Questions on the Eye and Sense of Sight 192 

The Ear and the Sense of Hearing — Parts of the Ear — The Outer Ear — 
The Middle Ear— The Bones of the Ear— The Eustachian Tube— The 
Internal Ear — The Nerve of Hearing — Sound — How we Hear — Deaf- 
Mutes— Care of the Ear — Synopsis of the Ear and the Sense of Hear- 
ing—Questions on the Ear and the Sense of Hearing. 202 



CHAPTER XII. 

Stimulants and Narcotics. 

Stimulants— Definition and Examples — Alcohol and Alcoholic Drinks- 
Properties of Alcohol — Spirit — Uses of Alcohol — Tinctures — Fermen- 
tation—What caused by — Kinds of — Acetous Fermentation — Vinegar 
— Vinous Fermentation — What due to — Distillation — Yeast Plant — ■ 
Varieties of Alcoholic Drinks — Beer — Ale — Porter and Stout — Cider 
— Manufacture of Beer, Ale, and Porter — Malt — Wines — Varieties of 
Wines — Red and White — Sweet and Dry— Home made Wines — ■ 
Liquors — Varieties — Whiskey — Brandy — Gin — Rum — Absinthe — 
Cordials — Bitters and Tonics — General Effects of Alcohol and Alco- 
holic Drinks — When Prescribed by Physicians — Not a Food — Intox- 
icating — Injury to the World which Alcohol Does — Effect of Alcohol 
on Bodily Warmth — On Muscular Force — On Brain and Intellect — 
On Tissues of the Body— On Stomach and Intestines— On Liver — On 



12 CONTENTS. 

Heart and Blood vessels — On Muscles — On Brain and Nerves — On 
the Eye — Effect on Power to Kesist Disease and to Recover from Ac- 
cidents — Delirium Tremens — Moral Effects of Alcohol— Alcohol 

Habit — Narcotics— Examples — Opium and Morphine— Laudanum 

Uses of — Opium or Morphine Habit — How Used — How Contracted 
— Effects of — Chloral — Appearance of — Uses of — Chloral Habit — 
Cocaine— Uses of — Cocaine Habit — Tobacco — Where Grown — How 
Introduced — Nicotine — Effects on System — Disagreeable Effects of 
Habit — Objections to Habit — Special Objections to Chewing and 
Snuffing — Synopsis — Questions 208 

Glossary 225 

Index 239 



CHAPTER I. 
INTKODUCTION. 

1. The human body is the highest form of living being-; 
consequently, greater care is required to keep it in health 
and to ward off disease than is the case with the lower ani- 
mals. 

2. Hygiene. — The study of how to take care of the body 
and how to prevent disease is called Hygiene. It is a very im- 
portant subject. "An ounce of prevention is worth a pound 
of cure " is an old saying, and is certainly a true one. If we 
wish to avoid sickness we must keep our bodies healthy. In 
order to know how to do this, we must learn about the things 
around us which are harmful and poisonous, so as to avoid 
them ; we must become acquainted with what is good and what 
is improper in our food, what are bad habits to be avoided, 
and also the injurious effects of drink containing alcohol, and 
of tobacco and other narcotics. All these things Hygiene 
teaches us. 

3. But if we are to remember them, we must understand 
how and why it is that certain things and habits are injurious ; 
and to do this intelligently, we must know something about 
the structure of our bodies, and the manner in which they per- 
form their work — that of living. 

4. Anatomy. — The study of the form and structure of the 
different parts of the body is called Anatomy. 

5. Physiology.— The study of how we live is called Phys- 
iology. It explains how we digest our food, how our blood 
circulates, how we breathe, grow, and move, and perform the 



14 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

many actions — some simple, some very difficult — which are 
necessary to life. It is a very interesting subject. 

6. These three branches — anatomy, physiology, and hy- 
giene — naturally go together. To explain their differences, let 
us take an easy example : Suppose a man wishes to be an 
engineer upon a locomotive. To perform his duties well there 
are many things connected with the locomotive which he must 
understand. In the first place, he must have a knowledge of 
the different parts of which it is built. This would correspond 
to the study of anatomy in the human being. Again, he must 
understand how the locomotive works — what causes the wheels 
to move, how steam is produced, and how to regulate the 
speed. This we would liken to the study of physiology in the 
human being. Finally, such an engineer must be acquainted 
with the proper care of his locomotive — what fuel to use, how 
to keep it clean, and other things to prevent it from getting 
out of order. Similar knowledge applied to the human body, 
hygiene gives us. 

7. We have been making use of the words life and liv- 
ing beings ; it is well to understand exactly what is meant by 
these. There are a great many different forms of life. The 
human being represents the highest form, while some very 
small animals, that cannot be seen except with the microscope, 
belong to the very lowest classes. Both are examples -of ani- 
mal life. In ordinary drinking-water we can see certain of the 
lowest forms of life if we look through a drop of such water 
that has stood for some time. These animals are so small that 
they must be magnified hundreds of times before we can see 
them ; they are perfectty innocent, and do no harm when we 
drink them. 

8. There is also life in plants, but it is different from that 
in animals. Plants grow, and also breathe. A few of them 
have the power of moving some of their parts, as the Venus 
Fly-trap. The leaves of this singular plant have a part at 
the top which opens and shuts just like a steel-trap. These 



INTRODUCTION. 15 

trap-like ends of the leaves are usually open when the sun 
shines, and whenever a fly alights upon one of them and 
brushes against the bristles that grow from its edges, the trap 
suddenly closes, capturing the insect and usually soon depriv- 
ing it of life. 

9. Differences between Plants and Animals.— The 
main differences between plants and animals are : — 

(1.) Plants exist upon ivater, gases, and mineral matters 
found in the earth. This would not be enough to support 
life in animals. 

(2.) Plants consist of different materials from those form- 
ing animals. 

(3.) Plants have no organs of digestion, such as possessed 
by animals. 

10. Organ. — The word organ, applied to the human body, 
means a part which performs some special work. For instance, 
the stomach is one of the organs of digestion, because it helps 
to prepare the food so that the blood can be nourished by it ; 
the eye is the organ of sight ; the tongue is the organ of 
taste. 

11. Function. — The special work which any organ of the 
body does is called its function. Thus, it is the function of the 
ear to hear, of the heart to propel the blood through the blood- 
vessels. 

SUBDIVISIONS OF THE BODY. 

12. We may divide the body in many different ways : 

(1.) Into different parts of the body ; such as the head, 
the trunk, the limbs. These again may be subdivided. 

(2.) We may further divide these into the different tis- 
sues. A tissue is one of the simple forms of material of 
w T hich the different parts of the body are composed ; thus, 
the finger consists of bone, fat, muscle, arteries, veins, 
nerves, skin — all these are tissues. 

(3.) If we subdivide still further, and again and again, 



10 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



until we come to the very smallest part, we have the cell, 
the fibre, and a substance between these, which may be jelly- 
like or may be hard. The entire body is formed of mil- 
lions of these cells and fibres and this substance between 
them. They are all very small and we must use a strong 
microscope to see them. It is only when millions of them 
are gathered together that they form a mass large enough 
to be seen with the unaided eye. The cells are of dif- 
ferent shapes, but usually they are more or less rounded. 
The fibres are thread-like. 









Fig. 1.— Some Different Forms of Cells. Fig. 2.— A Collection of Fibres, Separated. 



PARTS OF THE BODY. 

13. The human body can be divided into : 

(1.) The head and neck. 
(2.) The trunk. 
(3.) The limbs. 

14. The Head and Neck. — The head has a large cavity 
for the brain, and smaller ones to receive the eyes, ears, nose, 
and tongue. It is divided into the crown (the top part), and 
the face. 



INTKODUCTION. 



17 



Cheek 
Chin 



Scalp. 

Forehead. 

Bridge of Nose. 




Ankle, 

Arch or Instep of Foot. 



Fig. 3.— The Names of the Different Parts of the Body. 

2P 



18 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

15. The Trunk is the part of the body between the neck 
and upper limbs above, and the lower limbs below. It has 
two large cavities : an upper one, called the chest or thorax, for 
the heart and lungs ; and a lower one, called the abdomen, for 
the organs of digestion. 

16. The Limbs are attached to the trunk. 

The upper limbs start from the shoulders. There are two, 
each consisting of an arm, a forearm, and a hand. Where the 
upper limb joins the trunk is the shoulder and the armpit. 
Where the arm and forearm meet, is the elbow. Where the 
forearm and hand meet is the wrist. The front of the hand is 
called the palm, the opposite side, the back of the hand. 
The fingers are named as follows : — 

First— Thumb. 

Second — Index finger. 

Third— Middle finger. 

Fourth — Ring finger. 

Fifth— Little finger. 
The lower limbs start from the hip. Each consists of a 
thigh, a leg, and a foot. Where the lower limb joins the trunk 
is the hip and the groin. Where the thigh and leg meet is the 
knee. Where the leg and foot meet is the anJde. The under 
surface of the foot is called the sole, the upper surface the arch 
of the foot, or instep. 



SYNOPSIS. 

Hygiene — Care of body and prevention of disease. 
Anatomy — Form and structure of parts of body. 
Physiology — How we live. 
Life — 1. Animals. 

2. Plants. 
Differences between plants and animals : 

1. Plants exist upon water, gases, and mineral matter! 
onlv. 



INTRODUCTION. 19 

2. Plants consist of different materials from those forming 
animals. 

3. Plants have no organs of digestion. 
Organ — A part which performs some special work. 
Function — The special work which an organ does. 
Subdivisions of the body : 

a. Structure — Tissues, simple forms of material : 

1. Cell. 2. Fibre. 3. Substance between. 

b. Parts : 

1. Head and neck. 3. Upper limb. 

a. Crown. a. Arm. 

b. Face. b. Forearm. 

c. Hand. 

2. Trunk. 4. Lower limb. 

a. Thorax. a. Thigh. 

b. Abdomen. b. Leg. 

c. Foot. 



QUESTIONS. 

1. What is hygiene ? 2. "What are some of the things which it 
teaches us ? 3. What is anatomy ? 4. What does physiology teach 
us ? 5. Mention some of the things which it explains. 6. Explain 
the differences between these three branches : Anatomy, physiology, 
and hygiene. 7. Is there more than one form of animal life ? 8. 
Give examples. 9. Do plants live ? 10. How do we know this ? 
11. Do plants ever have the power to move any of their parts ? 12. 
Give an example of this. 13. Mention the differences between 
plants and animals. 14. What is an organ of the body ? 15. Give 
examples of organs. 16. What is meant by the word "function?" 
17. Give examples of this. 18. How do we divide the body ? 19. 
Give an example of a part of the body. 20. What is a tissue ? 21. 
Give an example. 22. What are the very smallest subdivisions of 
the body called ? 23. What is a cell ? 24. What is a fibre ? 25. 
Name the three main parts of the body. 26. Into what parts can 
the head be divided ? 27. W T hat is the trunk and what large cavi- 
ties does it contain ? 28. Name the different parts of the upper 
limb. 29. Name the different parts of the lower limb. 



20 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 




.Back of Skull (Occiput) 



Bones of Spinal Column 
forming the Neck. 



Collar-bone (Clavicle). 

Upper End of Bone of Arm form- 
ing the Shoulder-joint. 



.Bone of Arm (Humerus). 



Hip-bone. 

. . Inner Bone of Forearm (Ulna). 
.Outer Bone of Forearm (Radius). 

j Upper end of Thigh-bone 

| forming the Hip-joint. 



Bones of the Wrist (Carpus). 

.Bones of the Hand (Metacarpus). 



Bones of the Fingers (Pha- 
langes of the Fingers). 



■ Thigh-bone (Femur i 



.Knee-pan (Patella) 



. .Inner Bone of Leg (Tibia). 
Outer Bone of Leg (Fibula). 



. . . Bones of Ankle (Tarsus). 
.Bones of Foot (Metatarsus). 

j Bones of Toes (Pha- 

1 langes of the Toes). 



Fig. 4.— The Skeleton, Viewed in Front. 



CHAPTER II. 
.THE FRAMEWORK OR SKELETON. 

17. The Skeleton is the name given to all the bones in 
the body taken together. These form a framework around 
which all the soft parts of the body are arranged, just as the 
walls and rafters of a building support the rest of it. In man, 
and in all the higher animals, the skeleton is on the inside, and 
the soft parts are placed around this bony framework ; in some 
animals, such as the crab and the lobster, the hard shell on the 
outside corresponds to the skeleton. 

18. Uses of Bones. — The uses of bones are : — 

(1.) To give the body support and to keep it erect. This 
we see especially in the spinal column and in the lower 
limbs. 

(2.) To protect soft parts which would otherwise be easily 
injured. The brain, for instance, is enclosed in a sort of 
oval box formed by a number of flat bones joined together ; 
and in the same way, the heart and lungs are protected 
from injury by the bones which form the chest. 

(3.) To give great strength and hardness, and at the 
same time leave the part elastic, as in the wrist and 
foot. In the foot, for instance, there are many small 
bones joined together in such a way that though they are 
strong enough to bear the weight of the body, they are 
still elastic enough to allow us to jump upon the foot 
without injury. 

(4.) Lastly, bones are necessary for the purpose of mo- 
tion ; for walking and running, for grasping objects, and 



22 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Bone of Forehead 

(Frontal). 
Upper End of Bone 

of Nose (Nasal). 
Cheek Bone (Malar) 

Upper Jaw 

Lower Jaw 



The Breast-Bone ^ 
(Sternum). 



Part of the Spinal] 

Column forming ! 

the Lower Part j 

of the Back. J 

Upper Part of the 

Hip-bone. f 

Upper End of the 
Thigh-bone, form- V - 
ing the Hip-joint. ) 



Bone of Right | 
Thigh (Femur), j 



Bight Knee - pan 
(Patella). 



Inner Bone of / 
Right Leg (Tibia). J 



Lower End of 
Bones of Right 
Leg, forming An- { 
kle-joint. J 




Back of Skull (Oc- 
ciput). 



Bones of Spinal 
Column forming 
the Neck. 

Upper End of Bone 
of Arm, forming 
the Shoulder- 
joint. 

j Bone of Arm (Hu- 



merus). 

One of the 

(Eighth). 



Ribs 



. The Elbow- joint. 

Outer Bone of 
Forearm (Radius). 

Inner Bone of 

Forearm (Ulna). 

Lower End or Tip 

of the Spinal 

( Column. 

.The Wrist (Carpus). 

' Bones of Hand 

(Metacarpus). 
Thumb. 

Index Finger. 



Bone of Left 
Thigh (Femur). 



.The Knee-joint. 



Outer Bone of Left 
Leg (Fibula) . 



Bones of Arch of 
Foot (Tarsus). 

.Bone of the Heel. 

Bones of the Toes 
(Phalanges of 
the Foot). 



Fig. 5.— The Skeleton, Viewed from the Side, with Outline of the Body. 



THE FRAMEWORK OR SKELETON. 23 

for performing the many actions required of us. The 
thigh-bones and the bones of the leg, for instance, are 
necessary for walking. Bones serve as points of attach- 
ment for muscles, and are moved through the action of 
these muscles ; they simply carry out the will of the 
muscles, and these again are directed by our nerves and 
brain. 
19. Number of Bones. — There are two hundred bones in 
the human body. 




Fig. 6.— The Upper End of the Thigh-bone, where it Forms Part of the Hip-joint, Sawed 
through Lengthwise, Showing the Porous and Spongy Nature of Bone in Its Interior, and 
also the Commencement of the Central Canal for the Marrow. 

20. Forms of Bones. — Bones vary very much in form and 
size. Some of them are long, as the thigh-bones (Fig. 21) ; 
others are small and short, such as the eight bones which form 
the wrist (Fig. 20) ; others are flat, as for example the bones 
forming the skull (Fig. 11) ; finally others are of very odd and 
irregular forms, such as the bones which form the spinal 
column (Fig. 16). 



24 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 




21. Structure of Bone. — Each bone is surrounded by a 
very hard layer on the outside, within which the bone is looser 

and porous, having a large num- 
ber of small spaces through which 
the blood-vessels run (Fig. 7). 
The long bones, as those of the 
arm, thigh, and fingers, are hol- 
lowed out in the centre, and in 
this canal we find a fatty sub- 
stance called 'marrow. This hol- 

Fig. 7.— A Thin Slice of Bone, Cnt lowing Out of the boiie makes it 

Crosswise, as Seen under the jyricroscope. 

lighter and also stronger than 
it would otherwise be. Bones are closely covered by a tough 
membrane called the periosteum, which gives additional strength 
and protection to them. They are 
of a pinkish color during life, on ac- 
count of the small blood-vessels run- 
ning through them ; when dead, the 
color of bone changes to white. 

22. If we take a thin slice of bone, 
and look at it under the microscope, 
we shall see a large number of dark 
spots, with small lines running from 
them (Fig. 7). They correspond to 
the minute spaces which exist even 
in the densest bone, and show that 
it is never entirely solid. 

23. Composition of Bone.— 
Bone is composed of two parts of a 
hard mineral substance containing 

great deal Of lime, and Of One part Hard Mineral Matter has been Dis- 
p n, j ' t ti 7 #■ rru solved out by Acid. 

oi a sort material like gelatin, lhe 

mineral substance gives the bone its hardness ; the soft mate- 
rial makes it tough and elastic. To prove this we have only 
to dissolve out the mineral substance bv a weak acid, and we 




a Fig. 8.— The Outer Bone of the 
Leg, Tied into a Knot after the 



THE FRAMEWORK OR SKELETON. 25 

find that we can now bend the bone in any direction because 
it has lost its hardness ; if it be long enough, we can even tie 
it in a knot without breaking it, as is shown in Fig. 8. 

24 If, on the other hand, we put the bone into the fire, the 
gelatine will be driven off, and then the bone will have the 
same form as before, but will be very brittle and crumble very 
easily. 

25. In the baby, the bones consist very largely of a soft 
material, called cartilage. This is the reason why the baby 
cannot stand, or, if it is allowed to stand too soon, the bones 
of the legs may become bent, because they are not yet hard 
enough to bear the weight of the body. Gradually, as the 
baby grows, the hard matter is added. In young persons the 
bones are always softer than in the aged, and therefore do not 
break so easily. In old persons there is less gelatine and a 
larger proportion of the brittle mineral substance than in 
youth ; hence their bones are more brittle and are more 
easily broken, or, as the surgeons would say, are more liable 
to fracture. 

26. Care of the Skeleton. — If we wish to have erect and 
graceful bodies when we grow up, we must take care of them 
while we are young. It is while we are young that the bones 
are still soft and easily shaped. We should always remember 
to stand and sit erect, with the chest thrown forward and the 
shoulders back ; in this way we may avoid stooping and round 
shoulders. 

27. We should not weai\any clothing which is too tight. How 
often do we see misshapen chests in girls because they have 
worn dresses which were too tight. Fig. 72 is the picture of a 
chest which has become deformed through tight dressing. If 
we compare it with Fig. 18, which represents a healthy chest, 
we cannot fail to notice the difference. 

28. We must be careful to get shoes of proper size ; for if 
they are too small or too pointed our feet will become deformed, 
our toes bent and crooked, and painful corns and bunions will 



26 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



result. Such deformities are shown in Fig. 10. Girls should 
not be allowed to wear high heels, as they crowd the foot into 
the front part of the shoe, thus making the toes overlap. 
Shoes with high heels do not support the weight of the body 
properly, because they throw the upper part of the body for- 
ward. Another objection to high heels is the danger of acci- 
dents from falling and of spraining the ankle. 

29. Fracture of a Bone. — When a bone is broken the ac- 
cident is quite serious, and is called a fracture. The doctor is 
called and he sets the bone, that is, he brings the two broken 





Fig. 9.— A Natural Foot. 



Fig. 10. — A Foot which has Become De- 
formed and Affected with Corns and Bunions 
as a Result of Tight and Til-fitting Shoes. 



ends gi the bone together, and keeps them in position by band- 
aging them to a piece of thin board so that they cannot be 
moved ; then a soft material is formed between the two pieces, 
which gradually hardens and joins the two ends together. If 
properly taken care of, a broken bone becomes united again in 
several weeks, and is then as strong as it was before. If we 
happen to break a bone we must remember to keep as quiet as 
possible until the doctor arrives, so as not to move the injured 
part, and thus make matters much worse. 

30. Effects of Stimulants and Narcotics.— Drinks con- 
taining alcohol, and the use of tobacco, may prevent our bones 



THE FRAMEWORK OR SKELETON. 27 

from growing to their natural size. Many boys smoke cigar- 
ettes because they think it makes them look big and manly. 
This is a mistake. No one will consider them so because they 
smoke, and the habit often results in preventing them from 
growing to their natural size. The bones of drunkards break 
more easily than do those of others. 

31. If we wish to be large and finely built we must try to 
preserve our health, for when the health suffers the growth of 
the bones is interfered with. 

Having studied about bones in general, let us now examine 



THE DIFFERENT PARTS OF THE SKELETON". 

32. "We may divide the skeleton into four parts : — 
(1.) Bones of the head. 

(2.) Bones of the trunk. 

(3.) Bones of the upper limbs. 

(4.) Bones of the lower limbs. 

33. Bones of the Head. — The bones of the head taken 
together form the skull (Figs. 11, 12, and 13). The skull is 
made up of twenty-two bones. Eight of these are joined 
together at the upper and back part, forming an oval box of 
bone in which the brain is contained, and called the cranium. 
The front part of the skull, formed by the remaining fourteen 
bones, is called the. face. 

34. The Cranium. — The portion of the cranium which 
forms the forehead is called the frontal bone (1, Fig. 13). In 
the lower animals, such as the dog and the cat, the forehead is 
very low and slanting ; in the negro race it is less slanting ; 
while in the white races it is almost upright. Usually the 
prominence of the forehead indicates the development of the 
brain ; and in those who have spent much time in study it is 
usually very prominent. Behind, the cranium is formed by the 
occipital bone (3, Fig. 13). Above, two bones, known as the 
parietal (2, Fig. 13), join together to form the top of the skull. 



28 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



On the side of the head, just below where the hair ends, is a 
spot called the temple ; the bone which forms this part of the 
skull is called the temporal bone (4, Fig. 13). 

35. Most of the bones of the cranium have ragged edges look- 
ing like the teeth of a saw (Figs. 12 and 13), and when the 
bones are joined these teeth fasten the bones together just as if 
you spread out the fingers of one hand and then put them in the 




Fig. 11.— The Skull, Front View. 



spaces between the fingers of the other. In this way the bones 
are firmly united, and yet there is space between the edges so 
that they can give a little. This space is very important, for if 
these bones could not give at all, every blow upon the head 
would injure the soft, delicate brain within. The muscles, skin, 
and hair on the head also serve to break the force of blows. 

36. The Face. — Looking at the skull in front (Fig. 11) we 
see two large openings just below the forehead, which are 



THE FRAMEWORK OR SKELETON. 



29 




Fig. 12.— The Human Skull, Looked at from the Side. 




Fig. 13— The Bones of the Skull Separated. 1, Frontal; 2, Parietal; 3, Occipital; 
4, Temporal ; 5, Nasal ; 6, Malar ; 7, Upper Jaw ; 8, Lachrymal ; 9, Lower Jaw. 



30 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



known as the orbits and receive the eyes. Below and between 
these is the triangular opening of the nose, bounded above by 
two small bones (5, Fig. 13) called the nasal bones. To the 

outer side and below the orbits 
are the bones which form the 
prominence of the cheeks, and 
are called the malar bones (6, 
Fig. 13). At the lowest part 
of the face are the two jaws, 
the upper (7, Fig. 13) and the 
lower (9, Fig. 13). The upper 
jaw is firmly joined to the rest 
of the skull ; the lower jaw re- 
sembles a horseshoe in shape, 
and is separate from the rest 
of the skull, though connected, 
of course, during life, to the 
sides of the face by strong 
bands and muscles. Each jaw 
has a circular row of teeth, 
about which more will be said 
in the chapter on Digestion. 
Between these two rows of teeth 
is the mouth. 

37. The skull rests upon the 
upper end of the spinal col- 
umn and is very movable, so 
that it can be bent forward or 
backward, or from side to side, 
and can be turned in any direc- 
tion. 

38. Bones of the Trunk. — The bones of the trunk are: 
the bones forming the spinal column, the hip-bone, the collar- 
bone, the shoulder-blade, the breast-bone, and the ribs. 

39. The Spinal Column. — This is the row of bones 




^TLl • r 




Fig. 14.— The Spinal 
Column, as 
from Front. 



Seen 



Fig. 15.— The Spinal 
Column, as Seen 
from the Side. 



THE FRAMEWORK OR SKELETON. 



31 



which extends from the skull above to the lower limbs below. 
There are thirty-three of these bones piled one upon another ; 
bat in the grown person there are fewer, because the lowest 
nine bones unite so as to form but two ; of these five form the 
upper one, called the sacrum, and four unite to form the tip of 
the spinal column, called the coccyx. There are thus really 
but twenty-six separate bones in the spinal column. Each of 
these twenty-six bones is called a vertebra, and all of them 
taken together are known as 
the vertebrae. The spinal col- 
umn is often called the back- 
bone, on account of its extend : 
ing along the middle of the 
back. The vertebras are con- 
nected by circular plates of 
gristle, or cartilage, and by 
fibres. This cartilage and the 
fibres are elastic, and thus 
it is that our backbone is 
very movable — we can bend 
it in any direction or twist it 
because the cartilage gives. 
This also explains why it is 
that at nio'ht we are a trifle 

° . Fig. 16.— Three Vertebras from the Lower 

shorter than in the morning, Part of the Spinal Column, Separated. 

for the weight of the body has 

caused these plates of cartilage between the vertebras to be 
compressed slightly, while after a rest during the night, they 
regain their usual thickness. There is an opening in each of 
the vertebras, and when they are all in position, these openings 
connect and form a canal, the spinal canal, which runs all 
through the backbone. This canal holds the delicate spinal 
cord, from which nerves emerge through small openings on 
each side of the spinal column. At the upper end of the spinal 
canal it communicates with the cavity of the skull by means of 




32 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



a large oval opening, through which the spinal cord and the 
brain are directly continuous. If you run your finger along the 
middle of the back, you can feel projecting points ; these are 
the tips of the vertebrae. 

40. The Hip-bones (H, Fig. 21 and Fig. 17) are the two 
large and strong bones which are placed on each side of the 
lower end of the spinal column, forming with it a sort of basin 
which is called the peloid. On the outer side of each hip-bone, 




flG. 17.— The Pelvis, formed by the Lower End of the Spinal Column and the Hip-bones. 



at about its middle, will be noticed a deep, round depression ; 
in this fits the upper end of the thigh-bone. 

41. The Collar-bone, or Clavicle (Figs. 4 and 19, G), is 
the curved bone which we feel at the upper part of the chest in 
front, being connected with the breast-bone at its inner end. 

42. The Shoulder-blade, or Scapula (Fig. 19, B), is the 
large triangular bone which we feel at the upper part of the 
chest behind. It lies behind the upper ribs. At its outer 
angle is a round depression into which the upper, ball-like end 
of the bone of the arm fits. 

43. The Breast-bone, also called the sternum (Fig. 19, S), 



THE FRAMEWORK OR SKELETON". 



33 



is a flat bone, broad above and gradually tapering toward 
its lower end. It forms a strong guard to the front of the 
chest. Along its edges the ribs are attached on each side. 

44. The Ribs. — There are twenty-four ribs, twelve on each 
side. They are long, slender, curved bones, which form the 
outer boundary of the chest. They are very elastic. All the 
ribs are joined behind to the vertebrae of the back. The first 
seven are attached to the breast-bone in front, and are called 




Fig. 18.— The Chest, or Thorax. 



true ribs ; the last five are not attached to the breast-bone 
in front, and are called false ribs ; the upper three of these, 
namely, the eighth, ninth, and tenth, are connected with carti- 
lage in front, but the last two are entirely free in front, and 
are called floating ribs. 

45. The Chest, or Thorax (Fig. 18). — It has already been 

explained that this is the large cavity just below the neck which 

serves to hold the heart and lungs. These organs are of great 

importance, and are nicely boxed in by the bones we have just 

3P 



34 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



studied ; namely, the breast-bone in front, the ribs on each 
side, the collar-bone above, and the backbone behind. There 

are, of course, spaces between 
these different bones, but in 
the living body they are filled 
with muscles. A flat sheet of 
muscle-tissue also bounds the 
chest below and separates it 
from another cavity, situated 
just below it, the abdomen. 
This muscular partition is 
called the diaphragm. 

46. Bones of the Upper 
Limb. — These are: the bone 
of the arm (humerus) ; the two 
bones of the forearm (radius 
and ulna) ; and the small bones 
forming the hand. 

47. The Bone of the Arm 
is a single bone, known as the 
humerus. It is a strong bone 
and extends from the shoulder 
to the elbow. Its upper end 
has an enlargement, shaped 
like a ball, which fits into the 
cup-shaped depression, seen at 
the outer angle of the shoulder- 
blade. 

48. The Bones of the 
Forearm. — There are two 
bones in the forearm, an outer, 
the radius, and an inner, the 

Fig. 19.— The Bones of the Upper Limb. , mi -i n • -i i 

6\ Breast-bone (Sternum): C, Collar-bone. Ulna. They are placed Side D\ 
(Clavicle); B, Shoulder-blade (Scapula) ; A, . -, ., l««4«»««,, +1-.^™ 

Bone of Arm (Humerus) ; F, Bones of Fore- Side, the Space between them 

^ne?of d Hano? na): * Bones of Wrist ; ** being filled with a membrane 




THE FRAMEWORK OR SKELETON. 



35 



and Hand. — There are 
The hand may be divided 



and muscles. They extend from the elbow to the wrist. In 
twisting the forearm the radius revolves around the ulna, which 
is the less movable of the two. 

49. The Bones of the Wrist 

twenty-seven bones in each hand, 
into three parts : The wrist, or car- 
pus; the palm, or metacarpus ; and 
the fingers, or phalanges. The wrist 
is the most solid part and is made 
up of eight small bones, more or 
less rounded or cubical in shape, 
closely held together by tough 
bands. This arrangement serves to 
make the w T rist very strong and 
still very light. The bones form- 
ing the palm of the hand are five 
in number. Each finger has three 
bones, the end of one being joined 
to that of the other, except the 
thumb, which is shorter and has 
but two such phalanges ; this ar- 
rangement of the bones of the fin- 
gers allows them to move very 
dexterously. 

50. Bones of the Lower 
Limb. — These comprise the thigh- 
bone (femur), the bones Of the leg Fig 20.— The Bones of the Wrist and 

X1 ' Hand. Above is also seen the lower 

(tibia and fibula), the knee-pan (pa- ends of the radius and ulna, taking 
, 77 N , , , , ' „ , - e , part in forming the wrist-joint. 

tella), and the bones 01 the foot. 

51. The Thigh-bone, or Femur, is the largest and strong- 
est bone in the body, and is surrounded by more muscle than 
any other bone. Where it is attached to the hip-bone it has a 
large spherical part called its head, and this forms an angle with 
the rest of the bone by a part called the neck. Below, the thigh- 
bone joins with the bones of the leg and with the knee-pan. 





36 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



52. The Knee-pan, or Patella, 

is the small, round, flattened bone 
which can be felt at the knee. It 
serves as a protection to the joint, 
and often saves it from injury in falls 
and blows. 

53. The Bones of the Leg. — 
There are two bones in each leg. The 
inner bone is the shorter and stronger 
of the two, and is called the tibia. 
The outer bone is longer and more 
slender; it is called the fibula. These 
two bones, placed side by side, extend 
from the knee to the ankle. 

54. The Bones of the Foot. — 
Each foot is formed by twenty-six 
bones, one less than in the hand. 
Seven of these form the solid back 
part of the foot, called the tarsus, 
which includes the heel ; five form the 
arch or instep, also known as the met- 
atarsus ; and the remaining fourteen 
form the toes or phalanges. Thus, it 
will be seen, that there are as many 
bones in the toes as in the fingers ; 
but the toes are much less movable, 
being simply intended for support of 

21, — the body and for walking ; however, 
the Lower when they are trained to do other 

Limb. .B, the . 

lower end of things, they may become almost as 
column (Sa- nimble as the fingers are. The heel is 
cyx) ; //, "the the most solid part of the foot and the 
the P T°high- strongest, The sole of the foot, be- 
vll$™%*B*™oIt£V£ tween the heel and the toes, forms an 
( JS?Fi d t. Fibnla): *' the B ° neS ^ch at the inner border of the foot; 




THE FRAMEWORK OR SKELETON. 37 

which arch breaks the force of jumps from heights. If we are 
compelled to jump from a height, there is the least disagree- 
able effect and danger to the body if we alight on our toes, or 
just behind the toes, upon the soft cushion known as the ball 
of the foot, for when we reach the ground upon the heel, the 
shock is transmitted through the entire body, and gives rise to 
a very disagreeable sensation, and possibly even to injury. 

SYNOPSIS. 

Position — 1. Internal in higher animals. 

2. External in some, of lower animals. 
Uses of the bones : 

1. Support to rest of body. 

2. Protection to delicate organs. 

3. Strength and hardness. 

4. Motion, by serving as points of attachment for muscles. 
Number of Bones : Two hundred. 

Forms of Bones : 

1. Long. 2. Short. 3. Flat. 4. Irregular. 

Structure of Bone : 

1. Outer dense layer. 

2. Interior porous and light. 

3. Central canal filled with marrow in long bones. 

4. Blood-vessels pass through it, giving pink color during 
life. 

5. Covered by membrane (periosteum). 
Composition of Bone : 

1. Animal matter — About one-third in amount. 

Larger proportion in early life. 
Gives toughness and elasticity. 

2. Mineral matter — About two-thirds in amount. 

Larger proportion in advanced life. 
Gives rigidity. 
Care of the Skeleton : 

1. Avoid faulty positions, to prevent stooping and round 
shoulders. 

2. Avoid tight clothing, to prevent deformed chests. 



38 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

3. Avoid faulty shoes, to prevent deformities of the feet, corns, 
bunions, and accidents. 

4. Extensive indulgence in stimulants and narcotics (alcohol 
and tobacco) may prevent bones from growing to natural size. 

5. When general health suffers, growth of bones is inter- 
fered with. 

Fracture of a Bone : 

1. " Setting" the bone. 

2. To prevent further injury, the broken part should be kept 
quiet until the doctor arrives. 

3. Method of healing by material binding the two ends to- 
gether. 



Parts of the skeleton 
1. The Head : 


: — 






a. Cranium 


— 1. Frontal. 










2. Parietal. 






b. Face- 


-1. 

2. 
3. 
4. 


3. Occipital. 

4. Temporal, 
Nasal. 
Malar. 
Upper jaw. 
Lower jaw. etc. 


etc 



2. The Trunk: 

a. Spinal column (composed of 33 vertebrae) . 

b. Chest (formed by vertebrae, sternum, clavicle, and ribs). 

c. Eibs— 1. True. 

2. False (including two floating ribs). 

d. Collar-bone (Clavicle). 

e. Shoulder-blade (Scapula). 
/. Breast-bone (Sternum). 

g. Pelvis (formed by lower end of spinal column and 
hip-bones. 

3. The Upper Limb : 

a. Bone of arm (humerus). 

b. Bones of forearm — 1. Radius. 

2. Ulna. 

c. Bones of hand — 1. "Wrist (Carpus). 

2. Palm (Metacarpus). 

3. Fingers (Phalanges). 



THE FRAMEWORK OR SKELETON. 39 

4. The Lower Limb : 

a. Bone of thigh (Femur). 

b. Knee-pan (Patella). 

c. Bones of the leg — 1. Tibia. 

2. Fibula. 

d. Bones of foot — 1. Heel (Tarsus). 

2. Arch (Metatarsus). 

3. Toes (Phalanges). 



QUESTIONS. 

1. What is meant by the word "skeleton?" 2. How does the 
skeleton of a crab and lobster differ from that of man ? 3. What are 
the uses of bone ? 4. How many bones are there in the human 
body ? 5. Mention the different forms of bones. 6. Which part of 
the bone is the hardest ? 7. How does the inner part of the bone 
differ from the outer layer? 8. W T hat is marrow ? 9. Of what sub- 
stances is bone composed ? 10. How can you show that bone is 
made up of these two substances ? 11. How do the bones of a baby 
differ from those of a middle-aged man ? 12. How do the bones of 
an old man differ from those of a younger man ? 13. Tell something 
about the care of the skeleton. 14. Why is it necessary to sit and 
to stand erect ? 15. What happens when we wear our clothing too 
tight ? 16. What is a fracture ? 17. What effect may alcohol and 
tobacco have upon our skeleton ? 18. What effect does smoking 
have upon the size of boys ? 19. Will the growth of our bones 
take place properly if our health is poor? 20. Into what four dif- 
ferent parts can we divide the skeleton ? 21. What are the bones 
of the head taken together called? 22. What is the cranium and 
how many bones join to form it? 23. How are the bones of the 
cranium united ? 24. Where is the frontal bone ? 25. What does 
the prominence of the forehead show ? 26. Where are the orbits ? 
27. What is peculiar about the lower jaw ? 28. Name the bones of 
the trunk. 29. What are the vertebrae ? 30. How many are there ? 
31. How are they connected together? 32. What opening is there 
in the spinal column ? 33. What can you say about the hip-bones ? 
34. Where is the collar-bone ? 35. Where is the shoulder-blade ? 
36. What is another name for the breast-bone ? 37. What is its 



40 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

use? 38. How many ribs are there? 39. What does a rib look 
like? 40. Which are the true ribs? 41. Which are the false ribs ? 

42. What is a floating rib, and which ribs are called floating ? 

43. What is the chest, and what does it contain? 44. What is 
another name for it ? 45. What bones form the boundaries of the 
chest ? 46. What is the diaphragm, and what cavities does it sep- 
arate ? 47. What bones are there in the upper limb ? 48. How 
many bones are there in the arm ? 49. How many in the forearm? 
50. How many bones are there in the hand ? 51. How is the wrist 
formed ? 52. How many bones are there in each finger ? 53. How 
many bones are there in each lower limb ? 54. Which is the largest 
bone in the body ? 55. Describe the thigh-bone. 56. How many 
bones are there in the leg ? 57. Describe the knee-pan and its use. 
58. How many bones in the foot ? 59. Which are the more movable, 
the toes or the fingers ? 60. Which is the strongest part of the 
foot? 61. In jumping from a height, upon what part of the foot 
should we alight, and why? 62. What are the dangers of high 
heels? 63. What are the effects of too small or badly-formed 
shoes ? 



CHAPTER III. 
THE JOINTS. 

55. Wherever two or more bones meet is a joint. Joints 
are necessary in order that, one part of the body may move 
independently of the other. If this arrangement did not exist, 
we should have to move the entire body whenever we wanted 
to move any part of it. If you' observe how a man walks when 
his knee-joint, for instance, is stiff and cannot be used, you will 
appreciate how useful joints are. The more joints there are in 
any part of the body the more movable is that part ; notice, for 
instance, how movable the fingers are and how many joints 
there are in the hand. 

56. According to the amount of motion which they permit, 
joints are divided into three classes : 

(1.) Immovable joints, in which there is no visible 
motion. 

(2.) Slightly -movable joints, in which there is slight mo- 
tion only. 

(3.) Movable joints, in which there is free motion. 

57. Immovable Joints. — The best example of this form of 
joint is seen in the skull. The flat bones of the skull are 
fastened together by means of the small projections from their 
edges. Such joints are called sutures. They are very well 
adapted to what is required here, because being closely joined 
they make a strong box of the bones of the skull, and yet they 
are capable of a very little motion, enough to break the force 
of blows upon the head. In this way they serve as additional 
protection to the brain. 

58. Fig. 22 shows the sutures which we find on the upper 
surface of the skull. In front, joining the frontal bone with 



42 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



the two parietal bones, there is a suture which extends across 
the skull from one side to the other. It is called the coronal 
suture, from the Latin word corona, which means crown, be- 
cause the front part of the crown of a king is supposed to 
rest upon this line. Behind, where the occipital bone meets 
the two parietal bones is another suture, called the lambdoid, 




Fig. 22. — View of the Skull from Above, Showing the Sutures. 



on account of its resemblance to the Greek letter lambda (A). 
Between these two sutures, the coronal and the lambdoid, is 
another which connects the tw T o parietal bones. It is called the 
sagittal suture, from the Latin word sagitta (an arrow), because 
it was thought to join the coronal suture as an arrow meets the 
string of a bow. 

59. Slightly movable Joints. — In these joints a fair 
amount of motion is allowed, but much less than in the next 
class — the movable joints. We find examples of slightly movable 
joints between the different vertebra forming the spinal column. 

60. Movable Joints. — These are the most numerous and 



THE JOINTS. 43 

the most interesting. In all movable joints the same general 
arrangement exists : the ends of the bones forming the joint 
are covered with gristle or cartilage, a dense, semi-transparent 
substance much softer than bone, acting as a cushion to the 
ends of the bones, so that they are not bruised or injured when 
the joint is moved, or when the ends are brought together 
forcibly, as in jumping. 

If two surfaces rubbing against each other were dry they 
would soon be rubbed off; hence it is necessary to keep a 
joint moist all the time. In machinery this is accomplished 
by oil. In the living body the same thing is done by a yellow- 
ish fluid looking like the white of an egg, which constantly 
covers the ends of these bones. This fluid is given off from 
the inner surface of a sac which lines all movable joints. This 
sac or membrane is called the synovial membrane, and the fluid 
which it gives off is called synovial fluid. The ends of the 
bones forming joints are held in place and connected by strong- 
bands of tough tissue, which pass from one bone to the other, 
and are called ligaments. This is shown in Fig. 23, which 
represents a joint cut in two ; the bands on the outside, one 
on each side, passing from the upper to the lower bone, are 
the ligaments. Sometimes these are so extensive as to sur- 
round the entire joint, and thus be a cover to it. This entire 
covering is called the capsular ligament, because it is like a 
capsule ; this is seen in Fig. 24 

61. Varieties of Movable Joints.— There are four varie- 
ties of movable joints : 

(1.) Gliding-joint — in which one bone slides upon the 
other, as between some of the small bones forming the 
wrist, 

(2.) Hinge-joint — in which one bone swings forward and 
backward from the end of the other, just as a door opens 
and closes upon its hinges. A good example of this form 
of joint is seen in the connection of the arm with the fore- 
arm at the elbow. 



44 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



(3.) Pivot-joint — in which one bone turns upon the othei 
by an arrangement resembling a pivot. This is seen in 
the connection between the skull and the upper end of the 
spinal column. 




Fig. 23. — One of the Movable Joints Sawed 
through Lengthwise, with the Different Parts 
in their Proper Position, thus Showing the 
General Arrangement in Joints. 




Fig. 24. — The Hip-joint, Showing the 
Capsular Ligament Surrounding the Junc- 
tion between thejHip-bone Above and the 
Thigh-bone Below. 



(4.) Ball-and-socket -joint. This is a form of movable joint 
in which the greatest amount of motion is allowed. One 
bone ends in an enlargement like a ball which fits into a 
socket of the other bone ; hence the term ball-and-socket. 
Examples of this form of joint are seen in the shoulder 
and hip. 
62. Accidents to Joints. — When one of the bones which 
forms the joint is not in its correct position and no longer fits 
on the end of the other, we say that it is out of joint or dis- 
located. This accident is very painful. The bones must be put 
in joint again by the surgeon. Often the capsular ligament 
is torn. The accident is usually the result of falls. Many such 
falls take place in getting off street-cars, especially if the car 



THE JOINTS. 45 

has not come to a full stop, and the person does not remember 
to get off facing the horses. 

SYNOPSIS. 

Definition — The place of meeting of two or more bones. 

Uses — To allow greater freedom of motion. 

Varieties — According to amount of motion permitted ■ 

1. Immovable — no visible motion — sutures : 

a. Coronal. 

b. Lambdoid. 

c. Sagittal, etc. 

2. Slightly-movable — slight motion. 

3. Movable — free motion.' 

ji. Ends covered with cartilage. 

b. Upon this is synovial membrane. . 

c. Kept lubricated by synovial fluid. 

d. Bones connected and held in place by ligaments. 

e. Four different forms : 

1. Gliding-joint. 

2. Hinge-joint. 

3. Pivot- joint. 

4. Ball-and-socket-joint. 
Accidents — Dislocations — out of joint. 

QUESTIONS. 

1. What is a joint in anatomy? 2. What advantage is there in 
having joints in the body? 3. What classes of joints are there? 
4. Give an example of an immovable joint. 5. What is a suture ? 
6. Name the most important sutures of the skull, and describe each 
one. 7. Give an example of a slightly movable joint. 8. Describe 
the general arrangement in movable joints. 9. How are such joints 
kept moist? 10. What is cartilage ? 11. What are ligaments ? 12. 
How are the ends of bones forming joints held in place ? 13. What 
is a capsular ligament? 14. What forms of movable joints are 
there? 15. What is a gliding joint? 16. Give an example. 17. 
What is a hinge joint ? 18, Give an example. 19. What is a pivot 
joint? 20. Give an example. 21. What is a ball-and-socket joint? 
22. Give an example. 23. What is a dislocation ? 



46 ANATOMY, PHYSIOLOGY, AND HYGIENE. 




Fig. 25. -The Muacles of the Human Body (the Skin having been Removed). 



CHAPTER IV. 
THE MUSCLES AND MOTION. 

63. Thus far we have been studying the framework of the 
body and we found this to consist of about two hundred bones, 
which together we spoke of as the skeleton ; we found also that 
these bones were held together by tough tissues, called cartilage 
and ligaments ; we saw that there were a great many joints, so 
that one bone could move upon another. All these formed the 
framework. Now will be considered some of the tissues which 
cover the framework, or fill up the spaces between the different 
parts of the skeleton. The first of these to be considered are 
the muscles. We will consider particularly that great mass of 
muscles which covers the skeleton. 

64. Function, or Work of the Muscles. — Muscles give 
us the power of moving the different parts of the skeleton. Our 
skeleton would be of very little value to us if we could not 
move the different bones ; just as the sails of a ship would be 
of little use unless there were ropes and pulleys to hold and 
move them. 

65. Description of Muscle-tissue. — Muscles are the red 
masses which we commonly call flesh. What the butcher 
sells as meat is a mass of muscles from some animal. Wlien 
we eat roast beef for our Sunday dinner we are consuming a 
number of large muscles from the ox. Muscle is of a blood- 
red color. We can separate each muscle into small fibres, 
which are thread-like bodies joined side by side to form a 
fleshy mass which we call muscle. If we look at such a muscle- 



48 ANATOMY, PHYSIOLOGY, AND HYGIENE. 




fibre under a strong microscope we see a peculiar striped ap- 
pearance, which shows that each muscle-fibre is composed of a 

large number of smaller pieces 
joined together at their surfaces 
(Fig. 26). 

66. Tendons. — Muscles are 
strong, but still they are too 
soft to be attached directly to 
bone; they would not hold. So 
that strong, tough cords, known 
as tendons, are attached to the 
muscles and connect them with 
the bones. The ten- 
dons are white and 
shining and hence can 

Pig. 26.-A Piece of a Muscle Sepa- easily be distinguished 
rated into its Fibres and Showing the ^ ° 

Striped Appearance of the Fibres. (Mag- from the muscles, 
nified several hundred times.) 

They are of great 
strength, and it is very rare for any of them to 
break. The central, thick, fleshy part of a muscle 
is called its belly. In Fig. 27 the belly of the mus- 
cle is marked B, the ends or tendons T. If you 
feel the fleshy mass on the front of the forearm, 
you are feeling muscle. But if you put your finger 
at the wrist, and open and close your hand, you 
will feel hard cords move ; these are the tendons 
of the muscles of your forearm and serve to attach 
the muscles to the bones of your fingers. 

67. Fat. — The different muscles always have a 
little fat mixed with them which cannot be sepa- fig. 27.— a 
rated. But, besides this smaller quantity, there m°u I'c i e . leS B Y 
is more or less fat in layers between the different Tendons. 2 ' ' 
muscles ; there is also fat covering the muscles and 
between the muscles and the skin. Meat free from fat is said 
to be lean. 



T 



THE MUSCLES AND MOTION. 49 

68. Uses of Fat. — A certain amount of fat is necessary, 
and it is useful in the following ways : 

69. (1.) It keeps the body ivarm. Fat does not allow the 
heat of the body to pass out readily, and so it protects us from 
the cold. 

70. (2.) It protects the body from pressure. Just beneath the 
skin is a layer of fat, thick at some places, and thin at others. 
Where the body is exposed to much pressure the layer of fat is 
thick, preventing us from feeling the weight of the body. In 
the palms of the hands and the soles of the feet, for example, 
there is much fat ; otherwise our hands and feet would ache 
every time we used them considerably. 

71. (3.) Fat is a food. When persons are deprived of food 
they may live for a number of days, for the fat of their bodies 
is changed into nourishment which the blood takes up and 
furnishes to different parts of the body. As examples of this 
we have cases in which persons w 7 ho were shipwrecked, or who 
stowed themselves away in the hold of a ship so as to steal a 
passage, have survived many days. The tissue which suffers 
most is the fat ; this disappears, and on this account such 
persons rapidly become very thin. 

72. (4.) Another use of fat is to give a fine appearance to the 
body. It fills up the uneven spaces that would be left between 
muscles and bones. If it were not for this the entire body 
would be uneven and lumpy. In the baby, where the muscles 
are small and undeveloped and there is considerable fat, the 
outline of the body is nice and round. As the baby gets older 
the muscles become larger, and the amount of fat smaller, 
and the body is no longer so plump and rounded. Where the 
muscles are well exercised much of the fat is absorbed and the 
muscles stand out prominently. Bat still there is always some 
fat present. 

73. Kinds of Muscle-tissue. — Muscle-tissue is of two 
kinds. One variety, to which most muscles belong, is under 
the control of the will ; hence such muscles are known as volun- 

4P 



: 



50 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

tary muscles, directed by the will. Such muscles remain in a 
state of rest until we desire to use them. All the muscles on 
the outside of the body are of this class. The muscles of our 
arm, for instance, remain at rest during sleep, and at other 
times when we do not care to make use of them. Voluntary 
muscle-tissue appears striped when looked at under the micro- 
scope. 

74. The other class of muscles we call involuntary, that is, 
not directed by the will. These muscles are situated inside the 
body ; as examples may be mentioned the heart, the layer of 
muscle which is found in the walls of the stomach and intes- 
tines, and the muscular fibres in the walls of the arteries 
and by which these blood-vessels are made to contract. We 
cannot control the action of these muscles ; they act without 
our being conscious of it, and it is well that it is so. Take 
the heart, for instance ; day and night it is at work pumping 
the blood into the blood-vessels, to be carried all over the 
body. If we had to watch over this organ, to see that it 
kept on beating, we should always have to stay awake ; and 
if we were careless and fell asleep, and the heart stopped be- 
cause we were not directing it to keep on beating, life would 
soon cease. As another example, let us look at the working of 
the stomach. After food enters this organ the muscular fibres 
in its wall begin to contract and move the food about, so as to 
break it up into finer particles ; this is done without our know- 
ing anything about it, and without our being able to control 
it. Involuntary muscle-tissue presents no striped appearance 
under the microscope. 

75. Mixed Muscles. — Some muscles belong partly to one 
class and partly to the other ; for instance, the muscles be- 
tween the ribs, which move the latter in breathing. These 
act all the time ; yet we may not be aware of their action, which 
continues whether we are asleep or awake. Still we can stop 
breathing for a very short time, or we can breathe more rap- 
idly than is natural for a very short time — but only for a short 



THE MUSCLES AND MOTION. 



51 



time. These muscles are partly voluntary and partly involun- 
tary. 

76. How Muscles Act.— When a muscle acts we say it 
contracts; and as a result it causes some part of the body 
to move. If we watch a muscle while it is contracting we find 
it becomes shorter, broader, thicker, and at the same time 



4 





Fig. 28.— A, a Muscle at Rest ; B, the 
same Muscle Contracted. It has become 
shorter, broader, and thicker. 



Fig 29.— The Action of the Biceps Muscle 
of the Front of the Arm. (The dotted fig- 
ure shows the effect of the contraction upon 
the position of the forearm.) 



harder. Place your left hand upon the front of your right 
arm ; now bend your fingers into the palm of your right hand 
and then bend your right forearm upon the arm ; you will feel 
the muscle on the front of the arm become hard and swell up 
— it has become shorter, thicker, and harder. Since the mus- 
cle cannot break loose from its attachment to bones, it must 
bring these bones nearer together when it shortens. Fig. 28 
shows a long, fleshy muscle at rest [A), and the same muscle 



52 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

after contraction (having become shorter, thicker, and broader), 
to the right (B). In Fig. 29 the manner in which the contrac- 
tion of a muscle causes motion is shown. The picture illus- 
trates the biceps muscle on the front of the arm. It is attached 
above to the shoulder-blade (which is the fixed point), and be- 
low to one of the bones of the forearm (the movable attach- 
ment). The dotted figure shows the muscle after it has con- 
tracted — in order to shorten it must bend the forearm, so as 
to bring its two points of attachment nearer together. 

77. Though muscles have the power to contract, they cannot 
do this unless we direct it ; and the order to act comes from 
the brain. If the brain wishes a certain muscle to act, it sends 
it a message, and then the muscle responds. This message goes 
from the brain to the soft, whitish matter in the canal running 
through the centre of the spinal column, known as the spinal 
cord ; from the spinal cord the message is sent directly to the 
muscle by certain white threads, which we call nerves. 

78. This whole arrangement is very much like a telegraph 
office : the brain corresponds to the office to which messages 
come and from which messages are sent out, and the nerves 
we may liken to the telegraph wires or messengers which carry 
the despatches. The following example will illustrate this : 
Suppose you see an orange on the table before you. The eye 
sends a message to the brain, by means of the nerve of the eye, 
that the orange is there. You are heated and thirsty, and 
would like to eat the orange. The brain then sends out a mes- 
sage to the muscles that move your fingers and to those that 
move your arm that they are to seize the orange, and they 
obey. The message from the brain was carried down through 
the nerve-tissue in the backbone, the spinal cord, then through 
the nerves of the arm to their smallest branches, w r hich pass to 
the muscles. 

79. Although the muscles contract, and thereby cause the 
movement of the arm, forearm, and fingers, they are only 
the servants of the brain and nerves ; without an order from 



THE MUSCLES AND MOTION. 53 

the brain through the nerves they could not move. This is 
proven by the fact that when, from an injury, the nerves of the 
forearm are cut across, the muscles of the forearm and hand 
become lame, and we say they are paralyzed. If we examine 
them we may find no change, but they can no longer receive 
orders to act from the brain, and on this account are motion- 
less. 

80. Ordinary Muscular Movements are very Com- 
plex. — It is so easy for us to make use of our muscles that 
we are apt to believe every act which the}^ perform very sim- 
ple, but this is not the case. Even the very simplest acts in- 
volve the use of a great many different muscles. When we 
walk, for instance, we do not even give it a thought, yet very 
many different muscles are acting, each one with great skill 
and nicety. It is on this account that man cannot construct 
machinery that will perform many of the things done by his 
hands. No machine could be constructed, for instance, that 
could write, or draw, or paint to imitate the work done by hand. 
Even when we stand there are a number of muscles at work 
balancing the body. After standing a long time, owing to the 
fact that these muscles become worn out, we feel tired. 

81. Groups of Muscles. — Usually we find that muscles 
occur in sets, or groups, and that one set accomplishes just the 
opposite action from the other. Thus the muscles on the front 
of the forearm serve to close the fingers and hand, while those 
on the back of the forearm serve to open them. The large 
muscle on the back of the arm, called the triceps, straightens 
out the forearm, while the thick muscle in front of the arm, 
called the biceps (Fig. 30), bends the forearm upon the arm. 

82. All the different expressions of the face are produced by 
the action of the small muscles of the face. When they draw 
up the corners of the mouth they give rise to a look of pleasure 
and smiling ; if they draw down the corners of the mouth they 
produce an expression of sadness and displeasure. They may 
wrinkle the forehead horizontally and make the face look in 



54 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 




The Muscles of the Front of the 



Fig, 
Chest, Arm, and Forearm 



The fan-like 



muscle above and to the left is the " pec- 
toralis ; " in the centre of the arm is seen 
the " biceps." 



doubt, or wrinkle it vertically, 
producing a frown. There are 
many other varieties of expres- 
sion. The expression of the 
face soon becomes that wdiich 
the person himself habitually 
uses. If you look sullen and 
angry all the time the face will 
soon have this expression, be- 
cause the muscles become so ac- 
customed to acting in this way 
that they cannot do otherwise. 
In the same way you may have 
a constant silly expression, if 
you act the part of a fool every 
time you are with your com- 
panions. Some children are in 
the habit of twisting their eyes 
so that they look cross-eyed. 
This they often do to make their 
friends laugh. They should re- 
member that from constantly do- 
ing this the eyes may be injured. 
83. Number of Muscles. 
— There are about three hundred 
muscles on each side of the body, 
making about six hundred in all. 
Nearly all the muscles occur 
in pairs, that is, are the same 
on one side as on the other. 
A few muscles which exist in 
the middle line of the body 
are single. 

84. Shape of Muscles.— 
Muscles vary greatly in shape. 



THE MUSCLES AND MOTION 



55 



The most frequent form is that of a long, fleshy bundle with a 
tendon at either end for fastening it to bone. Sometimes they 
are flattened and placed in layers, as is the case in the muscles 
of the wall of the abdomen. Some muscles consist of flattened 
bundles which come together toward a single point like a fan ; 
such is the muscle of the temple — the temporal muscle. Other 
muscles are square-shaped, and still others form a circular 
ring ; so that there is great variety in the shapes of muscles. 

85. Size of Muscles. — Here, too, there are the greatest 
differences. Some of the muscles in the interior of the ear are 
only a fraction of an inch in length. Some of those of the eye 
are about an inch in length,- while the longest muscle is one 
which extends from the hip to below the knee, and is over two 
feet in length. Between these two extremes there are many 
different sizes. 

86. A Few Important Mus- 
cles. — It is not necessary for you 
to remember the names of many of 
the muscles, but there are a few 
which are worth remembering, be- 
cause they are important, and be- 
cause we often see them mentioned 
in books and newspapers. They are 
the following : 

87. The Biceps is the large fleshy 
muscle on the front of the arm, which 
bends the forearm upon the arm 
(Figs. 30 and 31). It can be felt 
upon making this motion. 

88. The Triceps is the muscle of 
considerable size which can be felt 
upon the back of the arm. It serves 

to straighten out the forearm after the biceps has bent it. 

89. The Chest-muscle, or Pectoralis (Fig. 30), forms the prom- 
inence at the upper part of the chest on each side. It is trian- 




— The Biceps and Tri- 
ceps Muscles. 



56 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



gular in shape, like a fan. It draws the arm inward across the 
chest. 

90. The Diaphragm is the sheet of muscle which separates 
the cavity of the chest from that of the abdomen. It is of 
great importance, and is one of the principal muscles concerned 
in breathing. It is an involuntary muscle. 

91. The Tendon of Achilles. — This is 
the strong, thick cord which you can feel at 
the back and lower part of the leg, just above 
the heel. It is the end of a very large and 
powerful muscle which raises the heel when 
we walk. It has received its name from the 
following story: Achilles was a Grecian hero. 
There was supposed to be a river, the Styx, of 
which it was said that whoever bathed in its 
waters could not be wounded. The mother of 
Achilles wishing to preserve her son from all 
future danger, dipped him into this river Styx, 
holding him by the heel. All parts of his body 
were wet except the heel by which he was held, 
and at this place he is said to have received his 
death-wound. 

92. The Care of Muscles.— The muscles 
form such a large part of the body that they 
soon show changes whenever our health is poor. 
During sickness, they waste away and become 
smaller. Even after being confined to bed for a 
few days we are surprised to find how weak PlG 
we feel on getting up, and how difficult it is SfeLeg.^o^n^Be- 
to stand. During this short period our mus- Jj^^ 6 Tendon 
cles have become weaker because we could not 

exercise them. So in order to get strong muscles they must 
be much exercised. 

93. Exercise. — Look at the arm of a blacksmith and see 
how well-developed his muscles are. This is because he is 



THE MUSCLES AND MOTION. 57 

constantly exercising them. In the same way the legs of a 
man who walks or runs a great deal will be well developed, 
and become prominent and hard. It is a fine sight to see a 
man who has large muscles which stand out and make him look 
strong and manly. Such a man is not so apt to get sick as 
another ; he feels stronger and may be more useful in the 
world because of his strength. 

94. All children should exercise regularly and sufficiently. It 
is not enough to walk slowly to school each day ; if this is all 
the exercise a person takes his muscles will become small and 
weak, and he will become delicate. Children should have at 
least two or three hours exercise each day. The best exercise is 
that which is taken in the open air. 

95. Playing with one's companions is the best kind of 
exercise, because it rests the mind and exercises the body 
at the same time. Fast walking, moderate running, row- 
ing, swimming, skating, bicycle - riding, and playing base- 
ball, foot-ball, tennis, and croquet are all good forms of exer- 
cise. 

96. We must remember to quit exercise when we begin to feel 
tired, for this is a sign that we have exercised enough and need 
rest. If exercise be continued too long it is harmful instead of 
beneficial. Many girls do themselves great harm by excessive 
exercise in jumping a rope, by trying to outdo their com- 
panions in the number of times they can jump without stop- 
ping. They often become greatly exhausted, and death has 
sometimes resulted. 

97. We should also avoid all violent exercise, for this does 
more harm than good. When boys try to lift heavy weights 
which would be a task even for men, or do too difficult feats in 
the gymnasium, producing too great a strain upon the muscles, 
it only harms them instead of causing them to increase in 
strength. 

98. Effects of Alcohol and Tobacco on Muscles. — Of 
all enemies to the development of muscle there are none greater 



58 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

than alcohol and tobacco. This is so well known that all per- 
sons who train in order to accomplish physical feats requiring 
unusual strength and the best of health, give up all use of 
tobacco and either use very little alcoholic drink or none at all. 
What alcohol is will be explained in another chapter. It will 
be sufficient to say here that all those drinks which, taken in 
any quantity, cause men to become intoxicated, contain alcohol 
and are called alcoholic drinks. 

99. The word train also requires explanation. It means to 
live in the most healthy way ; to go to bed early and rise 
early ; to eat the most digestible and strength-giving food ; 
to take plenty of out-of-door exercise; to avoid all tobacco; 
and to abstain entirely from drink' containing alcohol. All 
this is done to develop the muscles, so that one may be put 
in a fine and healthy condition, and become as strong as 
possible. 

100. Everyone has probably heard of the great boat-races 
which take place every year between Columbia and Harvard 
Colleges, and between Harvard and Yale Colleges. There is 
great rivalry between the colleges, and of course each likes to 
win the race. Each of these crews trains throughout the winter 
and spring until the day of the race, so as to become strong 
and increase the chances of winning. Every member leads a 
most regular life, and smoking and alcoholic drinks are absolute- 
ly forbidden. 

101. Alcohol is the enemy of muscle because it changes it into 
fat. When a muscle contains much fat it becomes weak and 
useless. Look at the drunkard and see how weak and flabby 
his muscles are. He may look big, but it is due to fat and not 
to muscle, and though he looks large he is bloated and puffed 
up ; he really is weak and tires easily. Nor is this all. The 
heart also is formed of muscle-tissue, and becomes changed to 
fat in the drunkard, when it cannot beat so strongly as it 
should. It becomes weak, and the blood is no longer pumped 
into the arteries as it should be, and the entire body suffers. 



THE MUSCLES AND MOTION. 59 

Sometimes there is so much fat mixed with the muscle of the 
heart that its wall becomes thin, and it may even burst ; then 
instant death ensues. 



SYNOPSIS. 

Function of Muscle —Power of moving parts of skeleton. 
Description : 

1. Red masses commonly called flesh. 

2. Divisible into fibres. 

3. Have the power of contracting or shortening. 

4. Three kinds are : # - 

a. Voluntary— Under control of the will — on outside of 
body. 

1. Appear striped under the microscope. 

2. End in tendons for attachment to bones. 

3. In contracting, become shorter, thicker, broader, 
and harder. 

b. Involuntary— not under control of the will — heart, 
walls of stomach and arteries, etc. 

1. Are not striped as seen under microscope. 

2. No tendons. 

c. Mixed— Consisting partly of voluntary, partly of in- 
voluntary fibres, such as muscles between the ribs. 

5. More or less fat between the fibres, between the different 
muscles, and covering them. 

6. Muscles usually occur in groups. 
Uses of Fat : 

1. To keep the body warm. 

2. To protect the body from pressure. 

3. To serve as a food. 

4. To improve the appearance of the body. 
The Way in which Muscles act : 

1. Become shorter. 

2. Become broader. 

3. Become thicker. 

4. Become harder. 

5. Bring together the parts to which attached. 



60 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

6. Dependent upon the influence of the brain, spinal cord, 
and nerves. 

7. Ordinary muscular movements very complex. 
Number of Muscles — About three hundred on each side. 

Shape of Muscles — Varies greatly : Most frequently, long fleshy 
bundle ; flat, fan-shaped, square-shaped, circular, etc. 

Size of Muscles — Varies greatly ; smallest, a fraction of an inch 
(found in ear) ; largest, over two feet in length (extends from hip- 
bone to leg). 

A Few Important Muscles : 

1. Biceps — Front of arm — bends forearm upon arm. 

2. Triceps — Back of arm — straightens arm. 

3. Pectoralis — Muscle of chest — draws arm across chest. 

4. Diaphragm — Involuntary muscle separating abdomen from 
chest — muscle of breathing. 

5. Tendon of Achilles — Just above heel — lower end of a large 
muscle of leg — has received its name from story concerning 
Achilles. 

Care of Muscles : 

1. They suffer when general health is poor. 

2. They need regular and sufficient exercise. 

3. Children should have at least two or three hours' exercise 
every day, in the open air. 

4. Good forms of exercise — Kapid walking, moderate running, 
rowing, swimming, skating, bicycle-riding, horseback-riding, 
base-ball, foot-ball, tennis, croquet. 

5. Stop exercise when beginning to feel tired. 

6. Avoid violent exercise. 

7. Effects of alcohol and tobacco on muscles : 

a. Enemies to the development of muscles. 

b. Alcohol changes muscle into fat — becomes weak and 
flabby. 

c. Alcohol changes heart into fat — becomes weak and 
does work poorly. 



THE MUSCLES AND MOTION. 61 



QUESTIONS. 

1. What use do we make of muscles? 2. What does muscle-tis- 
sue look like ? 3. What is it commonly called ? 4. What are mus- 
cle-fibres ? 5. What are tendons? 6. Of what use are tendons? 
7. What can you say about the appearance and the strength of ten- 
dons ? 8. How does fat occur with muscle ? 9. What are the uses 
of fat in the body? 10. What proof is there that fat is used as 
nourishment by the blood ? 11. Is there a larger proportion of fat 
in the baby or in the grown person ? 12. What three kinds of mus- 
cle are there ? 13. What is a voluntary muscle ? 14. Give an ex- 
ample ? 15. What is an involuntary muscle? 16. Give an ex- 
ample ? 17. Why is it necessary that some muscles shall be invol- 
untary ? 18. Give an example of the working of an involuntary 
muscle. 19. Do muscles ever belong to both classes ? 20. Give 
an example. 21. What do we mean when we say a muscle con- 
tracts ? 22. How does the muscle change when it acts? 23. Can 
the muscles contract of their own accord? 24. What causes the 
muscle to act? 25. What part does the brain take in the contrac- 
tion of muscles ? 26. What part do the nerves take in this ? 27. 
How can you prove that muscle itself cannot act without the influ- 
ence of the nerves ? 28. What two sets of muscles do we usually 
find together, and how does one set act toward the other ? 29. Give 
an example of two muscles which have exactly opposite actions ? 
30. How are the different expressions of sorrow, joy, and the like 
produced in the face ? 31. What may result from continually hav- 
ing an ugly or a foolish expression in the face ? 32. How many 
muscles are there in the human body ? 33. Do muscles usually oc- 
cur singly, or are they usually the same on one side of the body as 
on the other? 34. Mention some of the shapes of muscles. 35. 
How do muscles vary in size ? 36. Where is the Biceps muscle ? 
37. Describe the Triceps muscle. 38. Describe the Diaphragm. 
39. Describe the chest-muscle, and give its other name. 40. Where 
is the Tendon of Achilles ? 41. From what circumstance did it re- 
ceive its name ? 42. How does the condition of our health afreet 
the state of our muscles ? 43. What happens when we do not use 
our muscles ? 44. What effect has exercise upon our muscles? 45. 
How much exercise should children have every day ? 46. Where 



62 ANATOMY. PHYSIOLOGY, AND HYGIENE. 

is the best place to take this exercise, in the open air or in-doors ? 
47. What is the best kind of exercise for children ? 48. Mention 
some of the good forms of exercise ? 49. What effect has exercise 
when it is continued too long ? 50. What effect has exercise which 
is too violent and heavy ? 51. What effects have alcohol and to- 
bacco upon the development of muscle ? 52. What do you mean 
by alcoholic drinks? 53. What is meant by training? 54. What 
is the effect of training? 55. Why is alcohol injurious to muscle? 
56. What effect has alcohol upon the heart-muscle ? 



CHAPTER V. 
FOOD AND DKINK. 

102. As we shall see later, tlie different tissues of our bodies 
are being used up constantly. They are then replaced by ma- 
terials taken from the blood. The blood receives the nutritious 
matters from our food and drink. Of course, our food has to 
be changed very much before the blood can absorb it to build 
up the different parts of the body. When we drink milk we 
say it is nourishing, and no doubt it is ; but the milk must be- 
come changed in the stomach and intestines before it can enter 
the blood and circulate through the body to replace used-up 
tissues. 

103. Food and Drink are Essential to Life.— Without 
food and drink we could not live ; they are necessary for life 
and growth. We often hear of people fasting for a long time. 
It has happened that persons have lived for a few weeks with- 
out any food, but never without drink. If the body be deprived 
of both food and drink, death takes place, usually after several 
days. It is easy to see why this must be so. Even when we 
are as quiet as possible, the different tissues of our body are con- 
stantly changing, and are constantly being changed into material 
which is waste and must be cast off. We must breathe, and our 
heart must act constantly, and both of these are muscular ac- 
tions and consume nutrition furnished by the blood. If the 
blood does not get a sufficient supply of this from our food and 
drink, it must take it from the tissues, which would soon waste, 
and the person would die from weakness, because both blood and 
solid tissues would become changed so much that they would 
be unable to perform their functions. 



64 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

104. Difference in the Food of Plants and of Animals. 

— The food of plants is quite different from that of animals, 
being much more simple. Plants live upon air, the gases con- 
tained in the air, the moisture from the ground, and certain salts 
which are in the ground. These things are, of course, en- 
tirely too simple to support animals. Animals require some- 
thing more. If you should try the experiment of feeding your 
pet dog upon nothing but water, air, and salts, you would find 
he would become very thin and weak, and would soon die from 
lack of food. 

105. Difference in the Food of Different Animals.— 
Some animals live almost entirely upon flesh, and are therefore 
called carnivorous — a long word, meaning that they devour 
flesh. The cat, the dog, the lion, and the tiger are examples 
of this class. 

106. Other animals exist upon vegetables, grass, grain, and 
the like, and are therefore called herbivorous — that is, herb-de- 
vouring. Of this class the cow, horse, and rabbit are examples. 

107. Man belongs to neither of these two classes. He com- 
bines the two, requiring both fleshy and vegetable food. With these 
he must also have water and a certain amount of mineral salts. 

108. Fleshy Food. — By fleshy food is meant meat, whether 
from the ox, sheep, or other animal of this class, or from 
fishes. 

109. Vegetable Food. — This is the name given to the 
food which plants produce. It contains starch, sugar, and other 
matters. One variety of this kind of food contains a large 
amount of starch, and is therefore called starchy, or farinaceous 
food. Examples of this kind are wheat, which furnishes the 
flour from which bread is made, corn, barley, rice, oats, and the 
like. Hay also belongs to this class. Man could not, of course, 
eat hay, since his stomach is not arranged so that he could di- 
gest it ; but the ox eats hay, which is converted in his body 
into nutritious materials from which his flesh is formed, and 
the latter is then eaten by man. 



FOOD AND DKINK. 



65 



110. Starch. — It is important to understand thoroughly 
what starchy food is. You may have seen starch used for stif- 
fening linen. When used in this way, it is first mixed with 
water and then placed on the fire, which causes it to swell up 
and become changed into a paste. Kaw starch is not suitable 
for food for man ; it must first be made digestible by boiling. 
All starchy food must first be boiled before it can be used as 
food. The cow and ox can eat hay and oats and digest them ; 
but man would not think of taking oatmeal raw, but only after 




Fig. 33.— Starch Granules (from Potato) as Seen under the Microscope. 



it had been boiled. The same applies to rice, 
all other farinaceous food. There is no starch 
none in animals ; it occurs only in plants. 

111. Starch is a white powder which has a 
ing. When looked at under the microscope 
powder has a peculiar form and is marked 
(Fig. 33). 

112. Another form of vegetable food has a large quantity of 
sugar in it ; so that we are constantly takim 
food to form nourishment. 



farina, barley, and 
in fleshy food and 

strange, dry feel- 
each grain of the 
by rings or lines 



in sugar with our 



AND HYGIENE. 

113. Then it is also necessary that we should eat green vege- 
tables, as peas, spinach, string beans, salad, and the like. When 
deprived of these for any length of time, the blood becomes poor, 
and the body suffers. 

114. Fat and Fatty Food. — Fat or fatty food forms an 
essential part of our food. This is why we eat butter with our 
bread. The fat which we take in with our food may be vege- 
table, as for instance, certain nuts, or of tener animal food in the 
form of butter from cows' milk and the fat around meat. In 
the body, starchy and sugary food is changed into fat, and 
this is why we say that potatoes, bread, and the like are 
fattening. 

115. Water. — Water is even more necessary to life than is 
food. A person could live longer without food than without 
drink. The great drink is, of course, ivater. Three-fourths 
of the weight of the human body is water ; consequently water 
is an absolutely essential addition to our food. 

116. Tea and Coffee. — Much of the liquid which we drink 
is a decoction of tea and coffee. Grown people, while not usually 
harmed by either of these, sometimes make themselves nervous 
by drinking too much or too strong ; but both are injurious to 
children, for whom milk or water are the best drinks. Chocolate 
contains considerable nutritious fatty matter. Hence chocolate 
is more of a food, while tea and coffee are only stimulants — that 
is, they excite the system for the time only. Children do not 
need stimulants of any kind. 

117. Man must Combine all Forms of Food with 
Water. — Man is so constituted that he cannot exist upon any 
one form of food alone. Meat is very nourishing, but a man 
could not exist on meat alone ; he would soon become thin and 
weak. He must have meat, fatty food, vegetable food, and 
water, all combined. 

Some of the Simplest Forms of Food. — We will now 
consider some of the different forms of food. 

118. Meat and Fish. — There are a great many different 



FOOD AND DRINK. 67 

kinds of meat. Beef is used more than any of the others. 
There is always some fat mixed with the meat, even when we 
cannot trim off any more. Under this head also come chicken, 
turkey, and other fowl. Fish is a very useful form of fleshy 
food, and is usually quite easily digested. 

119. Bread. — Bread is made from flour. In America, this is 
usually wheat ground up fine. The baker takes the flour and 
adds water and a little salt, and with these he makes the 
dough. He also adds yeast, and will tell you he does this to 
make it rise, so that it will be light and easy to digest. What 
does the yeast do ? When it is added to the dough it changes 
some of the starch so that a gas' is given off. This gas escapes 
in bubbles, but cannot get through the dough. When it tries 
to work its way out, it puffs out the dough and makes it 
light and porous. Then this dough is put into the oven and 
baked, a hard crust forming on the outside. Bread is often 
called the staff of life on account of its importance. 

120. Milk. — Most of the milk used by man is obtained 
from the cow: but in some countries milk «-„ 

is obtained from the qoat and from the ass. $9&iM&££k% 
Milk is one of the 7iiost nutritious articles of .© "%©"' 

food, and at the same time one of the most S&lj 1$M% 

easily digested. Milk contains substances " @ - : fyi®* 

which are like all the different kinds of food jjjjf^f 

which man requires. It contains materials Fig. 34.— i Drop of 
like those found in flesh, fat, and others croscope" shoeing the 
which resemble those found in vegetable food, Fat -s lob « les (° ream )- 
and it contains a large amount of water. Thus it has in it 
everything that we require, so that we could live on milk with- 
out any other food. The baby thrives on milk alone for a long 
time, but after awhile man longs for more variety in his 
food. 

The fatty part of the milk, the cream, floats on top after the 
milk has stood for a time, when it can then be taken off. 

121. Butter is nothing but this cream pressed together. 



58 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Cream consists of fat-globules (Fig. 34). When milk is churned, 
these fat-globules stick together, and in this way form a mass 
called butter. 

122. Milk from which the cream has been taken is called 
skimmed milk, it then has a bluish tint, and is less nour- 
ishing. 

123. If we add a little piece of the stomach of the calf to the 
milk, it causes it to thicken or curd. This curd properly treated 
and pressed together forms cheese. 

124. Eggs are obtained from the hen, and from other birds 
of this kind. They are very nutritious and easily digested. 
The shell of the egg is lime. The contents of the egg consist 
of two parts, the white and the yellow. In the yellow or yolk 
of the egg is much fatty matter. Both portions of the egg 
correspond to fleshy food. 

125. Variety in Food. — We could not eat the same kind 
of food every day, for we should soon get tired of it ; it is neces- 
sary to have different kinds of food. Certain foods, however, 
as milk, butter, bread, beef, seem never to tire us. 

126. Proper Food. — If we wish to remain healthy we must 
not eat improper food. Girls who eat too much candy, or too 
many pickles, usually have very little appetite for any proper 
food, and soon become pale and delicate. And boys who eat 
green apples in summer, or unripe fruit of any kind, are sure to 
repent it. They are apt to become sick, and to have great pain 
in the stomach. 

127. Methods of Cooking. — Sometimes we eat our food 
raw, as, for instance, fruit ; but usually we cook it, because it 
becomes more digestible and tastes better. In cooking, we 
may make use of a great many different plans. If it is meat, 
we may put it into water and boil it, or if we let it get a little 
thicker, we stew it. We may put it into the pan with some fat 
and fry it. By holding it directly to the fire we broil, or roast 
it. Finally, by putting it into the oven, we bake it. Of all 
these different methods, boiling, stewing, and broiling, are most 



FOOD AKD DttlNK. 



69 



to be recommended, because they make the food the easiest to 
digest. 

128. You must remember also to take food at regular times 
in the day. Usually three meals a day are enough. Never eat 
in a hurry, but chew your food well. Never eat so much at one 
meal that you feel heavy, full, and uncomfortable. 

129. Our Drinking-water. — Water is the great drink, and 
it is very necessary that it should be pure. Clear water is not 




Fig. 35. — A Section of a Dwelling, and its Accompaniments, as is often Found in the 
Country. The shading extending from the stable to the layer of rock at the bottom of the 
well, shows the course of the poisonous material from the stable, with its manure- heap and 
pig-pen, to the well. 

always pure. Water may be very impure and still be very clear 
and transparent. And again, water may look a little cloudy, 
and yet be perfectly innocent and healthy. What makes some 
water unhealthy and injurious is poison dissolved from the soil. 
In cities where the water is brought from a distance in pipes, 
this poison is not apt to occur ; but in the country, where the 
water from wells is used, it is often present. In the country, 
very often no other water can be obtained except that from the 
well, and for the sake of convenience, the well is built near the 
house and the stable, where it is very apt to be poisoned. Fig. 



70 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

35 illustrates very nicely the manner in which the well-water 
may become poisoned. It is a good example of what occurs 
constantly in many places in the country where well-water is 
used without proper precautions having been taken to prevent 
poisoning. 

130. An examination of the picture on p. 69 shows the follow- 
ing : To the right is the dwelling-house ; to the left is the stable 
with its manure-heap and pig-pen ; between these two is the 
well. The surface of the ground is fairly level, and is sandy, 
and beneath this is gravel. The rain soaks into the porous 
ground, and in doing so dissolves poisonous matters from the 
manure-heap and the pig-pen, and after it has soaked into 
the ground it remains there, since there U a layer of rock be- 
low, which will not allow the water to pass. This poisoned 
water collects here, and then gradually enters the lower part of 
the well. When water is drawn from the well it will be easily 
understood that it is partly the same water which has passed 
over and through the manure-heap and the dirt of the pig-pen 
before passing into the ground. The shading extending, on 
the figure, from the stable to the bottom of the well, shows the 
course which this poisoned water tak r \ Such water causes 
typhoid fever and other diseases. 

It has often happened that a great many persons become sick 
in a village at the same time. When a great many persons be- 
come sick at the same time, and have the same disease, an 
epidemic is said to exist. Many epidemics have been found to 
have been produced by the drinking of poisoned well-water. 

131. The water of a pure river should be preferred to that of 
a well. But sometimes we have no choice and must drink well- 
water. In this case we should see that the well is thirty feet 
or more from any inhabited building, and that no refuse or 
slops of any kind are allowed to soak into the ground. Such 
refuse should be kept in water-tight barrels and carted off 
regularly. If we are in doubt about whether the water is good 
or not, we may boil it thoroughly ; this destroys the poison, and 



FOOD AND DRINK. 71 

then we are safe in drinking it. Varieties of filters are made, 
which are of value in freeing water from dangerous impurities ; 
not all filters, however, accomplish this purpose. 

132. Water which has stood in leaden pipes all night dis- 
solves a little of the lead ; hence when we use the water in the 
morning, we should allow it to run a few minutes before using 
any. 

SYNOPSIS. 

Uses of Food and Drink : 

1. To support Life. 

2. To allow growth. , - 
Differences in Food of Plants and of Animals : 

a. Food of Plants : 

1. Air. 

2. Gases in the air. 

3. Moisture from the ground. 

4. Salts from the ground. 

b. Food of Animals : 

1. Fleshy food (meat and fish). 

2. Fatty food. 

3. Starchy and sugary food, including green vegetables. 

4. Water (forms three-fourths weight of body). 
Differences in Food of Different Animals : 

a. Carnivorous — Flesh-eating. 

b. Herbivorous — Eating vegetables, grass, grain, etc. 

c. Man — Mixed food. 
Drink : 

Water. 

Tea and coffee — Unnecessary for children — often harmful. 
Necessity for Combining all Forms of Food with Water. 
Some of the Simplest Forms of Food : 

Meat and Fish — Beef most common. 

Bread — Should be light and porous. 

Milk — Most nutritious — contains : 

a. Cream, making butter. 

b. A material forming cheese. 
Eggs — Very nutritious. 



72 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Methods of Cooking : 

1. Boiled — Placed in water and heated. 

2. Stewed — Somewhat thicker than boiled. 

3. Broiled ) ' ,,.,-, 

4 t> f i ( — Exposed directly to fire. 

5. Baked — Placed in oven. 

6. Fried — Placed in pan with fat. 

Boiling, stewing, and broiling are most nutritious. 
Cautions Begarding Food : 

1. Variety. 

2. No improper food, such as much candy, unripe apples, 
etc. 

3. Regularity in meals. 

4. Plenty of time for meals. 

5. No overloading. 
Drinking-water : 

Should be pure. 
Clear water may not be pure. 
Healthy water may be a little cloudy. 
Danger of water from certain wells — 

Occurring through contamination from soil. 
Avoided by removal of well to distance of thirty feet or 
more from habitations, and removal of refuse without allow- 
ing it to poison the soil. 
Water from pure river preferable. 
Danger of poisoning from leaden pipes. 
Purification of suspected water by boiling or by passage 
through porcelain or other filters. 

QUESTIONS. 

1. Why must we take food and drink ? 2. What must happen to 
the food before it can be changed into our tissues ? 3. Describe the 
food upon which plants live. 4. Do all animals have the same kind 
of food? 5. What difference is there between the kind of food 
which the cow takes and that which the dog eats ? 6. What is 
meant by a carnivorous animal ? 7. What is meant by a herbivorous 
animal? 8. To which class does man belong? 9. What is meant by 
fleshy food? 10. What is meant by vegetable food ? 11. What is 






FOOD AND DRINK. 73 

farinaceous food ? 12. What is starch? 13. Do we find starch in 
animals? 14. Why is it necessary to eat green vegetables? 15. Do 
we need fat in our food? 16. Can man exist on any one form of food 
alone ? 17. Why do we naturally eat butter with our bread ? 18. 
How is bread prepared ? 19. Why is yeast added ? 20. Could we 
exist on milk alone ? 21. Why? 22. What part of the milk does 
the cream represent ? 23. What is butter ? 24. What is cheese ? 
25. What can you say about eggs as food ? 26. Could we eat the 
same kind of food every day ? 27. What follows when we eat im- 
proper food ? 28. Why is most of our food cooked ? 29. Name 
some of the different plans of cooking food. 30. What makes our 
drinking-water unhealthy? 31. Explain how well-water is often 
poisoned. 32. How can you prevent poisoning of well-water ? 



CHAPTER VI. 

DIGESTION. 

133. The word digestion means the changing of the food by 
the organs in the abdomen, so as to liquefy it in order that the 
blood can take it up and make tissues out of it. Digestion 
commences in the mouth and ends in the large intestine. If 
we commence from above, the following parts are met with : 
mouth, throat, gullet, stomach, small intestine, pancreas, liver, 
large intestine. All of these, except the pancreas and the 
liver, are hollow organs through which the food passes. All 
of these hollow organs taken together form the alimentary 
canal. Each of the organs of digestion will now be con- 
sidered. 

THE MOUTH. 

This is the commencement of the alimentary canal (Figs. 36 
and 67) and is the cavity in which the food is chewed and 
mixed with saliva. 

134 The Teeth. — The chewing is done by means of the 
teeth. These are supported by the jaws and occur in two rows, 
an upper and a lower. We do not have the same teeth when 
we are grown that we had when we were very small ; all the 
the teeth of young children fall out ; they are only temporary, 
and hence are called temporary or milk teeth. There are ten of 
these in each jaw, making twenty altogether. 

135. In the sixth year, or before, the temporary teeth begin 
to fall out, and after the sixth year, others commence to grow 



DIGESTION. 



75 



to take their places. These are stronger than those which grow 
first, and there are more of them. They are called permanent 




Fig. 36.— Outline Sketch of the Organs of Digestion. 



teeth ; and there are sixteen in each jaw. After the sixth year, 
the other permanent teeth gradually replace the temporary ones, 



76 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

which fall out. The last tooth to appear is that placed farthest 
back, called the wisdom-tooth ; this comes about the twenty- 
first year. 

136. Each tooth can be divided into the part which projects 




Fig. 37.— The Upper and Lower Jaws with the Permanent Teeth. 

into the mouth, above the gums, called the crown, the part which 
sinks into the jaw, the fang or root, and the line between these 
two, called the neck. Teeth are composed of a very 
hard material, consisting very largely of lime, called 
dentine. They are hollow in the centre (Fig. 38) and 
this central space is filled up with a soft material 
called the pidp. On the surface of the crown is a 
covering of very hard material, formed principally 
of lime, called enamel. Each tooth is supplied with 
a small nerve which enters it through an opening 
Section o?6iie i 11 the end of the root. It is the exposure of 
Teeth? M ° lar this nerve through the formation of cavities in 
the teeth which most often gives rise to toothache. 
137. Upon examining the teeth, we find they differ greatly 
in size and shape. They are similar on the two sides of the 
mouth and are the same in the upper as in the lower jaw. In 




DIGESTION. 



77 



Fig. 37 we see the teeth in position ; in Fig. 39 they are sep- 
arated, those on the right of the figure corresponding to 
the middle line, while those on the left are the back teeth. 
Commencing in the centre and proceeding toward each side 
(from right to left in Fig. 39) there are first two sharp-pointed 
teeth, having chisel-like edges, called the incisor teeth. Their 
sharp edges are intended to cut the food and to bite it into 
pieces. Next to these is a long, pointed tooth, called the 





Fig. 39. — The Permanent Teeth. Above are those of the upper jaw : below, those of the 
lower jaw. The teeth of one side of the jaw only are represented. The two teeth to the 
right are incisors. The long tooth next to these is the canine tooth. The following two 
are bicuspids. The last three (to the left) are molars. 



canine, also known as the eye-tooth. In the dog and cat, and 
animals of this type, this tooth is of great length and sharpness, 
and is used for tearing meat. Next to the canine are two 
broader teeth having two sharp points each, known as the bi- 
cuspid teeth. Still further back there are three large, broad 
teeth, the surface of whose crowns is very uneven, but they are 
very strong ; they are the molars and serve to grind up the 
food into small particles. 

138. The teeth are intended to chew the food so that it is in 
small enough particles to be received and digested by the 



78 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

stomach. Hasty eating results in the swallowing of food which 
has not been chewed sufficiently, thus causing indigestion, pain 
in the stomach, and, if continued, dyspepsia (which means dif- 
ficult digestion). 

139. Care of the Teeth. — Teeth are natural ornaments when 
nice and healthy ; but very disfiguring when dirty or de- 
cayed. Teeth should be brushed every morning upon rising, 
and every night before retiring ; they should be kept clean at 
all times. If particles of food lodge between the teeth, they 
should be removed with toothpicks of wood or quill ; never 
with pins, needles, or metallic points. Teeth are apt to decay 
and cavities to form, if the general health becomes poor, or if 
much improper food be taken. By improper food is meant, a 
great many pickles, much candy and cake, and food which is 
difficult to digest or too acid. Teeth should not be used to 
crack nuts with, nor for anything but chewing. When cavities 
have formed in the teeth, the dentist fills them with gold or 
silver foil to prevent them from decaying more. 

140. The vulgar habit of chewing tobacco discolors the 
teeth, makes the breath offensive, and injures digestion. 



THE SALIVARY GLANDS. 

141. We give the name glands to certain bodies, usually 
small and round, in which fluid is formed to be used in various 
ways. For instance, around the mouth there are many such 
glands, which form the saliva; that is, the fluid which con- 
stantly keeps the mouth wet, and moistens our food; hence 
these glands around the mouth are called the salivary glands. 
There are a great many of them, but most of them are very 
small. Three, however, are large and worth mentioning. 

142. The largest is placed in front of the lower end of the 
ear around the joint of the lower jaw, and has a small tube 
leading to the mouth. It is called the parotid gland. Another 



DIGESTION. 79 

is placed just below the tongue, and is therefore called the sub- 
lingual gland. A third is found underneath the chin on each 
side, and is called the submaxillary gland. 

143. These glands pour some of the saliva into the mouth 
all the time, but they are especially active when we use the 
jaws either in speaking or in eating. If it were not for this 
fluid, the mouth would soon feel dry after talking a little. In 
eating anything dry, as a cracker, we notice that enough 
fluid forms in the mouth to moisten it thoroughly and thus en- 
able us to swallow the mass. It would be difficult to swallow 
this if it were dry. When the saliva is mixed well with the 
food, the stomach can act on the food at once and digest it 
more easily. This is another reason why we should chew our 
food well. 

144. There is still another reason. A small part of starchy 
food is digested by the saliva before it reaches the stomach, 
thus aiding the stomach iii its work of digestion. 

145. Effects of Chewing Gum. — The habit of con- 
stantly chewing gum not only looks bad, but by making the 
saliva flow in large quantity all the time, it makes it thin and 
watery. Such saliva is apt to be inefficient in the proper per- 
formance of its work during meals. This habit is, therefore, 
not only vulgar, but unhealthy. 



THE THROAT. 

146. This is the wide part of the mouth behind, into which 
the food passes after it has been thoroughly chewed and when 
we swallow it. While we are swallowing, it passes into the 
throat. Once swallowed, the food passes into the canal leading 
to the stomach, the gullet, or oesophagus ; thence it continues 
its way without our knowledge or will (Fig. 36). 



80 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



THE TONGUE. 

147. This is also one of the organs of digestion, since by its 
movement the food is rolled around in the mouth and mixed 
thoroughly with saliva. The tongue also assists in swallowing. 
This organ will be described under the special senses, as it is 
also the organ of taste. 

THE GULLET, OR OESOPHAGUS. 

148. This is a long tube (Fig. 36) which connects the mouth 
and throat with the stomach. Its walls are formed of rings of 
muscle-tissue. When these rings contract, the food is forced 
downward until it reaches the stomach. 



THE STOMACH. 

149. The stomach is a bag about a foot long, placed in the 
upper part of the abdomen, just below the diaphragm. The 
latter, as has already been mentioned, is the sheet of muscle- 
tissue separating the abdomen from the chest. The stomach 
commences near the middle of the bod} 7 , and then extends over 
toward the right. There are two openings into the stomach. 
One is for the entrance of food, which is carried by the gullet 
from the mouth ; and in order to reach the stomach, the gul- 
let must, of course, pass through the diaphragm. The other 
opening of the stomach is at the farther end, and allows the food 
to pass on into the intestines after the stomach has done its 
work. Around this opening is a narrowing which remains 
closed until the food is ready to be sent to the intestines. 
This narrowing is produced by a thickening of the tissue at 
this point, and is called the pylorus. 

150. The wall of the stomach is not very thick, but it is very 
strong. On the outside there is a smooth, shining coat, which 
is merely a part of a membrane lining the whole inside of the 



DIGESTION. 



81 



abdomen and the organs within it. This membrane is known as 
the peritoneum. On the inside there is a soft, velvety coat, 




Fig. 40. — The Stomach, Showing the Layer of Muscle-tissue by which it Contracts and 
Propels the Food. 



called the mucous layer (Fig. 41). We often meet with the 
term mucous membrane in anatomy. It refers to a soft, smooth, 




Fig. 41. — The Inner Surface of the Stomach, Showing the Mucous Layer Arranged in Folds 



82 



velvety membrane which is called the mucous membrane be- 
cause it forms a watery, slippery fluid called mucus ; the fluid 
from the mouth between meals, and the fluid which runs from 
the nose are examples of mucus. Between these two surfaces, 
the mucous and the peritoneum, is a layer of muscle-tissue 
which forms the main part of the thickness of the stomach 
(Fig. 40). 

151. Gastric Juice. — The inner, or mucous layer of the 
stomach is arranged in a series of folds which are especially 
marked when the stomach is empty. It is usually of a pink or 
a grayish color, but its color and appearance differ greatly, de- 
pending upon whether it contains food or not. When food 

reaches the stomach, it excites it, 
and the soft lining then begins to 
swell, and becomes reddened. This 
mucous layer, when looked at under 
the microscope, shows a large num- 
ber of small dots or openings. 
When food is in the stomach, we 
can see drops of fluid escape from 
these dot-like openings. This fluid 
is called the gastric juice. 

152. The Gastric Tubules 
and the Gastric Juice. — The 
gastric juice is a very important 
fluid ; and it is found in the stom- 
ach only when food is present, 
which food causes it to flow. Of 
course the lining of the stomach 
is never dry, but it is moistened 
only with mucus, except when 
excited by food, when as just stated gastric juice begins 
to flow. Upon examining this internal layer of the stomach 
under the microscope, we find thousands of small tubes, lined 
by little oblong bodies, which we call cells (Figs. 42 and 43). 




Fig. 42 — A Section of the Lining 
Membrane of the Stomach Very 
Highly Magnified, Showing the Gas- 
tric Tubules in Position. 



DIGESTION". 



83 



These cells pour the gastric juice into the small tubes, and from 
these it passes into the stomach and is mixed with the food. 
But, it may be asked, from what do these cells take the gastric 
juice? They get it from the blood. There are tiny blood- 
vessels everywhere, and certain portions of the blood pass 
through the walls of the blood-vessels into the cells, 
and are mixed there with other substances ; and in Efs^^! 
this way the gastric juice results. 

153. Pepsin. — The substance in the gastric juice 
which enables it to digest fleshy food is called pepsin. 

154. Function of the Gastric Juice. — The 
work of the gastric juice is to digest food. But it 
does not digest every sort of food. It will digest only 
fleshy food. Vegetable food is digested elsewhere — 
a little by the saliva, but chiefly in the small intes- 
tine. Fat, also, remains undigested in the stomach, 
and passes on to be digested in the small intestine. 

155. (1.) Uses of the Stomach.— One of the 
uses we have just stated, namely, to digest the fleshy 
part of the food. 

156. (2.) The second use of the stomach is to be a 
storehouse for the food. It takes between two and 
three hours to digest an ordinary meal. If there Tubuie. the 
were no large bag in which the food could be kept 

until digested we should have to keep eating little by little all 
the time. The large size of the stomach also allows the gastric 
juice to be mixed quickly and thoroughly with the food, and 
thus digestion takes place more quickly than it otherwise would. 

157. (3.) Still another use of the stomach is to churn the 
food, and to roll it about so as to grind it into the smallest 
particles and mix it with the gastric juice. One of the coats of 
the stomach consists of muscle-tissue, and this coat causes these 
motions of the stomach. Besides, the lining of the stomach has 
a large number of raised lines or ridges (Fig. 41), which make 
the breaking-up of the food still easier. 



84 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

158. Some of the lower animals, as the ox and cow, have four 
stomachs. Such animals swallow grass and hay without thor- 
oughly chewing them. Afterward this food passes back into the 
mouth again. It is then chewed over again, swallowed, and 
after passing through the series of stomachs, is finally digested. 

159. Effect of Tobacco on the Stomach.— When a per- 
son smokes tobacco for the first time, it makes him sick at his 
stomach. He may get used to the tobacco after a while ; but 
still, if he smokes much, he has the same disagreeable sensation. 
Many persons make the stomach weak and delicate, and spoil 
the appetite, by smoking and chewing tobacco. 

160. Effect of Alcohol on the Stomach. — Alcohol irri- 
tates the stomach and reddens the lining. After a while it 
hardens it, thins it, and renders it unfit to digest the food 
properly. 

161. The Discovery of How the Stomach Acts. — 
Many years ago, a Canadian named St. Martin was shot in the 
abdomen. He recovered with a permanent opening leading 
from the outside into the stomach, through which the doctors 
could watch and see what happened after eating. They found 
that ordinarily it took the stomach from two to three hows to 
finish its work, and to discharge what it could not digest into 
the small intestine or bowel. This man lived a great many 
years with the curious opening, and was quite strong and 
healthy. 

162. Certain kinds of food require a longer time than other 
kinds for digestion, and hence we call them heavy or indigest- 
ible; other food is digested very quickly, and is called light, or 
easily digestible. As examples of heavy food may be men- 
tioned, hard-boiled eggs, pies, cheese, etc. As examples of 
easily digested food, there are milk, soft-boiled eggs, toast, 
broiled steak, etc. 



DIGESTION. 85 



THE BOWELS, OR INTESTINES. 

163. These consist of a long, hollow tube, about twenty-five 
feet long, commencing at the stomach (Fig. 36). Where stom- 
ach and intestines meet is a narrow opening, which is closed, 
except when the stomach has digested what it can of the food, 
and wishes to empty what is left into the intestines. 

164. This narrowing is called, as has already been mentioned, 
the pylorus, meaning gatekeeper, and it will be seen that it is 
well-named, for it guards the outlet of the stomach. The rem- 
nants of food which the stomach refuses to digest pass this 
point in the form of a soft, creamy mass. 



SUBDIVISIONS OF THE INTESTINES. 

165. The intestines can be divided into three parts ; the first 
part, which is next to the stomach, is called the duodenum, a 
long word, which was given to it in olden times because it is 
about as long as twelve fingers put side by side, so that this 
part of the bowel is quite short. The second part is very long 
— twenty feet — and forms the principal part of the bowels. It 
is called the small intestine, and the word small is used because 
it is narrower than the rest. The remainder of the bowels 
(about five feet long) is the last portion, called the large intes- 
tine, because it is wider than the rest. 

166. The intestines are twenty five feet long. In order that 
they may be contained in the abdomen they are folded together 
many times around a stem which is attached to the backbone. 
In this way they can move around somewhat, and yet they are 
kept in place by being held to the backbone. It will be seen 
later why it is necessary that they should be allowed a certain 
amount of motion so as to cause the food to move on. 

167. The intestines have the same coats a3 the stomach. 



86 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

There is on the outside a smooth, shining coat (the peritoneum). 
On the inside is a soft, smooth, velvety coat (the mucous 
coat). Between these two there is a coat formed of muscle- 
fibres, which run around the intestine in circles. There is 
much less muscle-tissue in the walls of the intestine than in 
those of the stomach. 

168. The Peritoneum. — The shining outside coat of the 
intestine is very important, and is formed of the same layer of 
tissue that lines the whole abdomen. The whole inside of the 
abdomen and the outside of all the organs within it are covered 
with this smooth sheet of tissue which we call the peritoneum. 
This covering is necessary so that the organs can move one 
upon another without paiu, injury, or friction. The smooth 
surface is always kept moist by fluid. 

169. Motion of the Intestines. — The intestines are never 
quiet. They are in motion all the time. This motion resem- 
bles that of a worm, slow, gradual, and creeping. It is ac- 
complished by means of the muscle-fibres which exist in the 
walls. The object of this motion is to propel the food along 
so as to spread it out and hasten the absorption of the liquid 
and nourishing portions of the digested food. 

170. Projections on the In-ner Surface of the Intes- 
tines. — The inner surface of the intestines looks pinkish and 
is velvety. It has a large number of valves or ridges (Fig. 44) 
running across it, which prevent the food from passing along 
too rapidly, so that all the nutritious portions may be absorbed. 
Besides these projections we find that the velvety appearance 
is due to the presence of millions of other very small projections 
(Fig. 45), which resemble hairs in shape, but are soft, and 
when looked at with the microscope are found covered with 
cells. We also find, when we examine the mucous lining of 
the intestines, a great many small tubes similar to those found 
in the stomach. 

171. The Work of the Intestines. — The intestines finish 
the digestion of the food. They also afford a lengthy surface 



DIGESTION. 



87 



over which the liquid and digested nutritious parts of the food 
can pass and be absorbed by the blood, which then brings them 
to different parts of the body. We found that a small part of 
starchy food is digested by the saliva and that the stomach di- 
gests the fleshy portions of the food. The intestines digest the 
rest, namely : (1) the larger part of starchy food which is not 
affected by the saliva, (2) the entire fatty portion of the food, 
and (3) any remnants of fleshy food which the stomach may 
have failed to act upon. 

172. Starch cannot be taken up by the blood until it has 




Fig. 44.— The Inner Surface of the Small 
Intestine, Showing the Valves or Ridges. 



1 






K-*i\ 



»•> 



4$ 



h 



■ k'J : OX* 






^JFXa'J 



Fig. 45.— The Small Hair-like Projections 
from the Inner Surface of the Intestine. 
(Very highly magnified.) 



become changed into sugar. Fat must also first become al- 
tered by fluids in the intestines before the blood can absorb 
it. 

173. Openings into the Small Intestine.— The main 
work of the intestine takes place at the upper part near the 
stomach. Just below the stomach we find two openings leading 
into the part of the intestine known as the duodenum. One 
of these openings is the canal from the liver and the gall-bladder. 



88 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



the other is the canal from the pancreas. Previous to discussing 
digestion in general, the organs furnishing these two canals 
"will be considered. 

THE LIVER AND THE GALL-BLADDER. 




Fig. 46.— The Liver, Upper Surface. 



174. The liver (Figs. 36, 46, and 47) is a large organ of a 
brownish color, placed in the upper part of the abdomen, to the 
right of the stomach. It is just below the diaphragm and the 




Fig. 47.— The Liver, Under Surface ; Below, the Gall-bladder is Seen. 



lower ribs, which cover it in front and above by forming an arch 
over it. The liver is very heavy ; it is smooth on the outside, 



DIGESTION. 



and covered by the same smooth membrane which covers all the 
organs of the abdomen, viz., the peritoneum. It is subdivided 
by deep lines into five sections called lobes. 

175. Uses of the Liver. — The liver is a very important 
organ. Its uses are, 

(1.) To make the bile. 

(2.) To purify the blood which passes through it. 
(3.) To add a certain nourishing body to the blood which 
passes through it. 

176. The Gall-bladder and Bile.— If we look at the liver 
under the microscope, so that it is very much enlarged, we shall 
see that it is formed entirely of 
small cells, like cubes, packed one 
ngainst another (Fig. 48). These 
cells manufacture the bile, which is 
then collected by small tubes. 
Along the lower edge of the liver a 
bag about the size of an egg will be 
seen. This is called the gall bladder 
(Figs. 36 and 47), and the tubes which 
collect the bile empty into it. This 
bag keeps the bile until it is wanted. 
The liver is making bile all the time and yet the intestines do 
not need it except when food is present ; hence there must be 
such a storehouse. 

177. Action of the Bile. — After the stomach has finished 
its work and the changed food has passed into the intestine, 
the bile which has been stored up in the gall-bladder is allowed 
to escape into the intestine by a small tube leading to one of 
the two openings in the duodenum already described. The 
bile is of a green or brown color. We do not know precisely 
what the bile does to the food ; but Ave are certain that bile 
must be mixed with it, for if it is absent a person cannot live 
very long. Sometimes bile gets into the blood and causes a 
yellow color of the skin, which we Qal\jau?idice. 




Fig. 48. — The Liver-cells, Very 
Highly Magnified. 



90 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

178. There is a great deal of blood passing through the 
liver, which is purified in its passage by the removal of certain 
unhealthy parts. 

179. After a meal there would be a great deal of nourishing 
matter thrown into the blood all at once ; and this would soon 
be used up and then there would be no more until the next 
meal. In order to prevent this, the liver takes care of a large 
amount of sugar and keeps it stored up, and then gradually lets 
it return little by little into the blood. 

180. The Unhealthy Liver. — Many sicknesses are caused 
by changes in the liver. If we eat too much at a time, or eat 
food which is too rich, as many wealthy people do, the liver be- 
comes diseased and does not remove the impurities of the 
blood as it should ; and these then remain in the blood and 
give much trouble. Perhaps some of you have seen old gen- 
tlemen limp along with the aid of a cane, unable to walk 
well because their big toes are swollen and sore ; they then 
have gout from too rich food, too much wine, and too little exer- 
cise. 

181. The Drunkard's Liver. — The liver suffers very 
much as the result of alcoholic drinking. It sometimes grows 
too large, and sometimes gets too small. The blood cannot 
flow through it as it should ; and so the liver cannot do its 
work properly. Thus the entire body suffers, and the most 
serious symptoms trouble the unfortunate man who leads the 
life of a drunkard. 

THE PANCREAS. 

182. This is one of the organs of digestion (Fig. 36). The 
pancreas of the calf is sold by the butcher as sweetbread. This 
organ is not large, but is very important. It is placed just 
below the stomach. Its work is to prepare a fluid called the 
pancreatic juice. This is made by cells, just as in the liver. 
Small tubes then collect the fluid and open into one large 



DIGESTION. 91 

tube which empties into the commencement of the small in- 
testine. 

183. Uses of the Pancreatic Juice. — The pancreatic 
juice digests all parts of the food which are left after the saliva 
and the gastric juice of the stomach have acted upon them. 
Thus it digests fat and starch, and it will also digest airy of 
the fleshy food which the stomach has neglected to change. It 
is consequently a very important fluid. 

ABSORPTION. 

184. All the fluids of digestion just described — the saliva, 
gastric juice, and pancreatic juice — simply change the chewed 
food, so that the blood can take it up or absorb it as nourish- 
ment ; and this action of these fluids is called digestion. There 
still remains to be seen how the blood absorbs this nourish- 
ment, and what it does with it. 

185. If we look at one of the smallest blood-vessels (Fig. 53) 
it will be found that the walls consist of the very thinnest 
membrane, and that this allows fluids to pass through quite 
readily. In the lining of the stomach and intestines we find a 
great many of these tiny blood-vessels ; as the food reaches 
these places and has become digested, it passes into the blood- 
vessels and is carried with the blood to the different parts of 
the body, to be used in forming and building up tissues which 
are constantly being consumed. 

186. Lacteals. — Besides passing directly into the blood- 
vessels, the digested food also passes into certain other tubes 
of very small size, like blood-vessels, except that they do not 
contain blood. These small tubes are called lacteals, from a 
Latin word meaning milk, because the nourishing fluid which 
they carry and afterward add to the blood looks white, like 
milk, during digestion. These lacteals finally empty into large 
veins at the lower part of the neck (Fig. 62). 



92 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



HABITS WHICH ARE INJURIOUS TO PROPER DIGESTION. 

187. (1.) Eating too rapidly. When the food is eaten too 
rapidly it cannot be chewed properly, and the result is that it 
is swallowed in large pieces. The stomach has great difficulty 
in digesting these large pieces and thus indigestion and dyspep- 
sia result if the practice be continued. 

188. (2.) Eating too much at a time. This gives the organs 
of digestion too much work to do, and on this account all the 
food cannot be digested. We should not continue to eat until 
we feel heavy and uncomfortable, but should stop before we 
feel this way. 

189. (3.) Eating too many sweets and sours. While a pickle 
occasionally at meals, or candy and cake now and then, will do 
no harm, if these things are taken constantly they are injurious, 
because they destroy the appetite for nourishing food. 

190. (4.) Chewing gum gives the salivary glands too much 
work, and thus the saliva soon becomes too thin and does not 
act as it should. 

191. (5.) A large amount of ice-water. A little ice-water, taken 
slowly, will do no harm, whether during meals or at other times ; 
but to drink down a gobletful rapidly when the body is heated 
is very unhealthy, as it chills the stomach and delays diges- 
tion. 

192. (6.) Violent exercise immediately after a meal. This 
should not be indulged in, for at that time the stomach needs 
all the blood it can get ; and violent exercise drives too great a 
proportion to the muscles. 

193. (7.) Severe brain work directly after meals is not good. 

194. (8.) Bathing should not be indulged in within two hours 
after an ordinary meal. 

195. (9.) Excitement of any kind, as good news or bad news 
just before a meal, usually takes away our appetite. If we eat, 
nevertheless, the food will not be digested, or only very imper- 
fectly. 



DIGESTION. 93 

196. (10.) Alcoholic drink makes food less digestible, espe- 
cially if it be strong drink ; and it also irritates the stomach 
needlessly. 

197. (11.) Smoking will destroy the appetite and interfere 
with digestion in many persons. 

THE SPLEEN 

198. The spleen (Fig. 36) is not one of the organs of diges- 
tion ; but its description will be given at this place, because it 
is placed in the abdomen. It is a round, flattened organ, solid, 
and contains a great deal of blood. It is found on the left 
side of the abdomen just underneath the low T er ribs. Its use 
is not exactly known ; but lately, however, it has been thought 
to take part in supplying the globules to the blood. It be- 
comes enlarged in all malarial diseases, and then sometimes 
reaches an enormous size. 

SYNOPSIS. 

Digestion — The changing of the food and its liquefaction, so that 
the blood can absorb it. 

Organs of Digestion : Mouth. 
Teeth. 

Salivary Glands. 
Tongue. 
Throat. 
Gullet. 
Stomach. 

c Duodenum. 
Intestines. < Small Intestine. 
' Large Intestine. 
Liver. 
Pancreas. 
Mouth — To chew the food and mix it with saliva. 

a. Tongue — Assists in mixing food with saliva and in 
swallowing. 

b. Teeth: 

-. j a. Temporary or milk teeth — ten in each jaw. 
I b. Permanent — sixteen in each jaw. 



94 



Four incisors. 
Two canine. 
Four bicuspid. 
Six molars. 

2. Divisible into 

( Crown. 

a. Parts : ■< Neck. 

( Boot. 
/ Enamel. 

b. Structure : ■< Dentine. 

( Pulp (cavity). 

3. Care of — Should be kept clean. 

Brushing. 
Toothpicks. 
Improper use. 
Tobacco. 
c. Salivary Glands : 

1. Location : 

(1.) Parotid — In front and below ear. 
(2.) Sublingual — Below tongue. 
(3.) Submaxillary — Below jaw. 

2. Saliva. 

(1.) Produced during chewing. 
(2.) Moistens food. 
(3.) Digests a part of starchy food. 
(4.) Keeps mouth moist. 
(5.) "Watery, clear fluid. 
(6.) Necessity for thorough chewing. 
(7.) Effect of chewing gum. 
Throat : 

1. Between mouth and gullet. 

2. Concerned in swallowing. 
Tongue : 

1. Mixes food with saliva. 

2. Assists in swallowing. 

3. Organ of taste. 
Gullet or (Esophagus : 

1. Connects throat and stomach. 

2. Formed of rings of muscle-tissue. 

3. These force food into stomach. 



DIGESTION. 95 

Stomach : 

1. Position — Upper part of abdomen, just below dia- 
phragm. 

2. Openings — One for entrance of food ; other (pylorus) 
into intestines. 

3. Coats : 

(1.) Outer — Peritoneum. 
(2.) Middle— Muscle-tissue. 
(3.) Inner — Mucous membrane. 

4. Uses : 

(1.) To secrete gastric juice, which — 

a. Is formed during digestion. 

b. Digests fleshy food. 

c. Contains pepsin. 

d. Is formed in the gastric tubules. 
(2.) A storehouse for the food. 

(3. ) To churn the food and break it into small particles. 

5. Effects of alcohol and tobacco — Alcohol irritates, to- 
bacco sickens. 

6. Discovery of action — St. Martin ; opening in stomach. 

7. Digestibility — Heavy and light food. 
The Intestines : 

1. Connection with stomach — By pylorus. 

2. Subdivisions: 

• a. Duodenum. 

b. Small intestine. 

c. Large intestine. 

3. Length — Twenty -five feet. 

4. Attachment — To backbone. 

5. Coats — Same as stomach : 

a. Outer or peritoneum. 

b. Middle or muscle tissue. 

c. Inner or mucous membrane. 

6. Motion — To propel food and digested fluids. 

7. Projections from inner surface : 

a. Valves or ridges. 

b. Hair-like projections. 

8. Function : 

a. Digest starchy food. 



90 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

b. Digest fatty food. 

c. Digest remnants of fleshy food. 
9. Openings : 

a. From liver and gall-bladder. 

b. From pancreas. 
The Liver and Gall-bladder : 

1. Position — Upper part of abdomen, to right of stom- 
ach. 

2. Description — Large, solid, brownish, subdivided into 
five sections or lobes. 

3. Uses: 

a. To make bile. 

1). To purify the blood. 

c. To add nourishment to the blood ; storehouse. 

4. Bile : 

a. Color — Greenish or brownish. 

b. Action — Not exactly known. 

c. If gets into blood — Jaundice. 

5. Unhealthy Liver — From too rich food, too much wine, 
too little exercise ; Gout. 

6. Drunkard's Liver — Too large or too small. 
The Pancreas : 

1. Position — Just below stomach. 

2. Use— To form pancreatic juice, which — 

a. Digests fat. 

b. Digests starch. 

c. Digests remains of fleshy food. 
Absorption— The taking up of digested food in fluid form by the 

blood and lymphatics : 

1. By blood-vessels. 

2. By lymphatic vessels. 

3. By lacteals. 

Habits Injurious to Proper Digestion : 

1. Eating too quickly. 

2. Eating too much at a time. 

3. Eating too many sweets and sours. 

4. Chewing gum. 

5. Ice-water in large amount. 

6. Violent exercise immediately after meals. 



DIGESTION". 97 

7. Severe brain-work immediately after meals. 

8. Bathing after meals. 

9. Excitement before, during, or after meals. 

10. Alcoholic drink. 

11. Smoking or chewing tobacco. 
The Spleen : 

1. Description— Bound, flattened, solid organ full of blood. 

2. Position — Left side of abdomen, underneath lower ribs. 

3. Use — Probably to supply globules to the blood. 

4. Enlarged — In malarial diseases. 



QUESTIONS. 

1. What is meant by the word digestion? 2. Name the organs 
of digestion ? 3. What are the teeth for ? 4. What are the tem- 
porary teeth ? 5. When do we begin to have our permanent teeth ? 
6. How many permanent teeth are there in each jaw ? 7. What are 
the parts of each tooth? 8. Are the teeth solid or hollow? 9. 
What names are given to the different teeth ? 10. Which are the 
incisor teeth, what is their shape and their use ? 11. What is pecu- 
liar about the canine tooth? 12. What about the bicuspid teeth ? 
13. What about the molar teeth ? 14. Of which three parts does 
each tooth consist ? 15. What is the proper way of taking care of 
the teeth ? 16. What effect has tobacco on the teeth? 17. What 
are the salivary glands ? 18. Where are they found ? 19. What is 
their use ? 20. What is saliva ? 21. What are the uses of saliva ? 
22. What are the effects of chewing gum upon the saliva? 23. 
Where is the gullet ? 24. Where does it lead to ? 25. What is the 
shape of the stomach ? 26. Where is it placed? 27. What open- 
ings are there in the stomach ? 28. What coats are there to the 
wall of the stomach ? 29. How does the inside of the stomach look 
when it is empty ? 30. How does it look when food enters the 
stomach ? 31. What is the gastric juice ? 32. How is the gastric 
juice made ? 33. Of what use is the gastric juice ? 34. When does 
the gastric juice flow ? 35. What kind of food is digested by the 
gastric juice? 36. What is pepsin ? 37. What are the three uses 
of the stomach ? 38. Have any animals more than one stomach ? 
39. How does the ox digest hay? 40. What effects have tobacco 
,and alcohol upon the stomach? 41. How was the way in which the 



98 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

stomach acts in man discovered ? 42. What is meant by heavy 
food? 43. What is meant by light food? 44. Give examples of 
each. 45. What is another name for the bowels ? 46. How long 
are the bowels ? 47. How do the bowels connect with the stomach ? 
48. What kinds of food are still undigested when they leave the 
stomach? 49. What is the pylorus? 50. Into what three parts 
can the intestines be divided ? 51. What is the name given to each 
part? 52. How are the intestines arranged so that they can all find 
room in the abdomen ? 53. To what are the intestines attached ? 
54. What coats have the intestines ? 55. What can you say about 
the outside shining coat of the intestines? 56. What is the peri- 
toneum, and what does it cover ? 57. Tell about the lining of the 
intestines. 58. What is the work of the intestines? 59. What 
kinds of food are digested by the small intestine ? 60. In what part 
of the small intestine does most of the work take place ? 61. What 
openings are there into the first part of the small intestine? 62. 
Where is the liver placed ?,. 63. What are the three uses of the 
liver? 64. Where is the gall-bladder? 65. How is bile made? 
66. What does it look like? 67. When is bile needed in the intes- 
tine ? 68. How does the bile get into the intestine ? 69. What 
can you say of .the uses of bile ? 70. What is jaundice ? 71. 
How does the liver become diseased? 72. What is the cause of 
gout ? 73. What effect has alcohol upon the liver ? 74. Where is 
the pancreas? 75. What is it commonly called by the butcher? 
76. What fluid is produced by the pancreas ? 77. What are the uses 
of the pancreatic juice ? 78. What kinds of food are digested by the 
pancreatic juice ? 79. How does the blood take up the nourishing 
parts of the food which have become digested ? 80. What are the 
lacteals, what do they do, and w 7 hy are they so-called? 81. Are 
the intestines usually quiet or in motion ? 82. Why is it necessary 
for them to be in motion ? 83. Mention some of the habits which 
are injurious to digestion ? 84. Explain why eating too quickly or 
too much at a time is injurious. 85. How should ice-water be 
taken ? 86. Why should we not exercise directly after meals ? 87. 
What effect has excitement of any kind upon digestion ? 88. What 
effect have alcohol and alcoholic drinks upon digestion ? 89. Where 
is the spleen? 90. What does it look like? 91. What do we know 
about its use ? 



DIGESTION. 



99 




Fig. 49.— The Blood-vessels. In the right half of the figure the arteries are shown ; in 
the left half, the veins. 



CHAPTER VII. 

THE BLOOD AND THE CIRCULATION— THE HEART AND 
THE BLOOD-VESSELS. 

199. If you cut your finger you notice a red fluid escaping 
from the wound which you call blood. If the cut be a slight 
one, only a little blood will be lost, and the accident will not 
worry you much ; but if it be deeper, you may have trouble in 
stopping the bleeding, and you would feel alarmed, for every- 
one knows how important the blood is. It is called life's fluid, 
and it deserves the name ; for if one -quarter of the blood is 
lost, life would be in danger ; and if one-third were lost, certain 
death would result. 

200. Appearance of Blood.— Blood is a thin fluid of a 
red color. If we look at the blood of an artery, the color is bright 
red ; but in the veins the blood is of a dark red color. Why 
this difference exists will be explained later. Although it has 
this red color, the fluid part of the blood is not red, but yellow- 
ish. It looks red because there are a great many small red 
bodies floating in it. These we call the blood-globules. 

201. Composition of the Blood. — The blood is composed 
of a yellowish fluid, called plasma, in which we find millions 
of small bodies, mostly of a red color, which we call the blood- 
globules. 

202. Blood-globules.— If we take a drop of blood and 
look at it under the microscope, we can easily see these blood- 
globules. Even in a small drop of blood, there are about ten 
millions of them, which will give an idea of the great number 
there must be in the entire body. 



THE BLOOD AND THE CIRCULATION, 



101 



203. The Microscope. — This instrument has often been 
alluded to in these pages, and is constantly 
used in studying the finer structure of 
different parts of the body. Probably 
everyone knows what a magnifying-glass 
is, and has seen it used for making objects 
look larger. Perhaps, too, many of you 
have brought the rays of the sun together 
into a small spot on your hand and found 
how this burns. On this account, the mag- 
nifying-glass is often called a burning- 
glass. Such a magnifying-glass makes 
objects appear five or six times as large as 
they really are. If several very strong 
magnifying-glasses were placed one over 
another in a metal tube (Fig. 50), objects 
looked at through all of them would 
appear a hundred, or even a thousand 
times larger than they really were, and 
this would constitute a microscope. 

204. Red Blood-globules.— If a drop of blood be looked 
at under the microscope, the yellow fluid is seen plainly, and 
in it we also see the blood-globules in great numbers. Most 

of these globules are of a reddish color, 
flat, with the edge a little thicker than 
the centre. These are called the red 
blood-globxdes. After the blood leaves 
the body, these red blood-globules are 
apt to stick together at their sides (Fig. 
51), and in this way columns are formed 
looking like rolls of coin piled one upon 
another. 

205. White Blood-globules.— Be- 
sides the red blood-globules there are others which are white, 
and somewhat larger than the red (Fig. 51). These are not flat, 




Fig. 50.— The Microscope. 




Human Red and 



White Blood-globules. The red 
globules are seen to be flattened 
and in rolls ; the white ones are 
alone, dotted, and larger. 



102 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



but perfectly round, like a sphere, and Lave two or three spots 
in their centre. There are very few of these white bodies, 
which we call white blood-globules, compared to the large number 
of the red ones. We call both the red and the white ones glob- 
ules, because of their shape, the word globule meaning a little 
sphere. 

206. The Plasma. — The watery, fluid portion of the blood 
in which the red and the white blood-globules float is called 
the blood-plasma. 

207. Blood of Other Animals. — In other animals, as in 
man, the blood is red and is formed of plasma, red blood-glob- 
ules, and white blood-globules. 
There is, however, one difference 
in some animals. In man the red 
blood-globules are flattened, cir- 
cular, and perfectly clear, having 
no spots in the centre. 

In many of the larger animals, 
and in all of our domestic animals, 
the red blood-globules have this 
same shape. But in the blood of 
birds, fishes, and certain other ani- 
mals like snakes and alligators, 
which we call reptiles, the red blood-globules, while still of the 
same color as in man, are oval in shape, and have a spot in 
the centre (Fig. 52). 

208. Use of the Red Blood-globules.— The red blood- 
globules have a very important use, to explain which it will be 
necessary to say something about the air we breathe. The air 
is made up principally of two gases : One-fifth is a rich gas 
called oxygen. It is the gas which is necessary for life. The 
rest is a gas called nitrogen, which serves to dilute the oxygen 
so that it may not be too rich, but just right for breathing. 
When we inhale air it passes into our lungs and stays there a 
short time, and while there the blood takes some of the oxygen 




Fig. 52.— The Red Blood-globules in 
Birds, Fishes, and Reptiles (on left of 
figure) as Compared with Those of Man 
(right half of figure). 



THE BLOOD AND THE CIRCULATION. 103 

from the air. In tbe lungs there are a great many small blood- 
vessels. The oxygen passes through the thin walls of these 
and the blood flowing along takes it up. The watery part of 
the blood cannot take up the oxygen ; the red blood-globules 
do this. At the same time the color of the blood, which was 
dark red before the oxygen was taken up, changes to a bright 
red. After the red blood-globules have taken up this valuable 
gas, they carry it to different parts of the body and give it to 
the tissues which have become used up, so that they become 
built up again. 

209. Use of the Plasma. — The fluid part of the blood also 
has a special use. When the- different tissues of the body are 
beiug used up, they give off a poisonous gas which is called 
carbonic acid gas. This gas is quite heavy and often collects at 
the bottom of wells or in cellars that have been dark and shut 
up for a long time. You sometimes read of people losing their 
lives by going down into such wells and cellars, for this gas is 
so poisonous that the people cannot breathe it and they choke 
to death. In such cases, if it is suspected that this gas may be 
collected there, a lighted candle should first be lowered into 
them ; if it will not burn, it would be dangerous there for a 
human being. For where this carbonic acid gas is present, the 
oxygen is absent or very little is present, and the candle re- 
quires oxygen to burn just as we do to breathe and live. After 
the plasma has taken up this poisonous carbonic acid gas, it 
carries it to the lungs where it passes through the walls of the 
blood-vessels and escapes into the air. This is the reason why, 
the air which we breathe out is not so pure as that which we 
breathe in. 

210. Difference between the Blood in Arteries and 
the Blood in Veins. — The blood flowing in the arteries is of 
a bright red color, because it has just received a supply of oxy- 
gen from the air in the lungs, and has given up its poisonous 
gas to the air. The blood in the veins is of a dark red color 
because the tissues have robbed it of the oxygen which it had 



104 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

before, and have given it a large supply of the poisonous car- 
bonic acid gas. The blood in veins is warmer than that of 
arteries. 

211. Clotting of the Blood.— While the blood is in the 
body and in the vessels through which it usually moves, it is 
fluid. But if taken from the body, and placed in the air, it 
very soon becomes thicker and thicker, and finally is a soft 
solid, about as thick as jelly. If in a cup, it may then be turned 
out, and like jelly, it will retain the shape of the cup. In addi- 
tion to the thick part, a quantity of yellow fluid will also be 
found to have separated. Blood never becomes hard, even 
when it solidifies ; it becomes a soft jelly-like solid. This 
change of the blood from the fluid to the solid state after it is 
removed from the blood-vessels is called clotting. The thick- 
ened blood we call a clot, while the yellow fluid which separates 
is called the serum. It is, of course, not natural for blood to 
clot ; this happens only when the blood is exposed to the air, or 
when there has been some change in the blood-vessel. It is 
quite difficult to understand why this thickening occurs, but 
if we examine the blood under the microscope after it has 
clotted we see that a large number of very fine hair-like bodies 
called fibres have appeared, and that these run in every di- 
rection and across one another, and that the blood-globules 
have been caught and entangled among them ; and this makes 
the blood thicken. 

212. Value of the Clotting of Blood.— This thickening 
or clotting of blood is of the greatest importance. If it were 
not for this we should bleed to death every time we cut our- 
selves. For when a wound is made, the blood flows until a 
crust forms, and this crust stops the bleeding. This crust is 
the same thickening, or clotting, of which we have been speak- 
ing, and there would be no way to stop bleeding permanently if 
it were not for this. You might press your finger on the wound 
and stop the bleeding in this way, but as soon as you took your 
finger off the blood would flow again. 



THE BLOOD AND THE CIRCULATION. 



105 



213. The Circulation. — Thus far we have been speaking* 
of the blood itself. Now we will study how the blood flows 
through the body, for our blood is constantly moving. This 
we can see very well in the frog. If we take some part of the 
frog, as for instance, one of the thin parts of the foot, and 
spread it out and look at it under the microscope, we shall 
see the blood in motion. The only reason we cannot see it in 
man is that there is no part thin enough and transparent 
enough for us to see through. If we examine the thin part 
of the frog's foot in this way we shall see a number of tubes, 




Fig. 53.— The Blood in Motion, as Seen in the Small Blood- vessels of the Frog's Foot. 



and in the centre a fluid full of small bodies— some reel, some 
white — these are the blood-globules. It will be seen that 
there are a great many red ones and only a few white ones. 
And you can also notice that the red ones hurry along, a great 
many in company, in the centre of the stream, while the few 
white ones seem to rub against the wall of the blood-vessel, 
and go along quite slowly. It is a beautiful sight and is an- 
other illustration of how wonderfully we are constructed. In 



106 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

studying the manner in which blood flows through our bodies 
it will be necessary to commence with a description of the 
heart, the arteries, the veins, and the capillaries. 

THE HEART. 

214. Situation of the Heart.— The heart is the most 
important organ in the body. It is placed in the chest, be- 




FiG. 54. —The Heart in Its Natural Position. It is surrounded by its sac, the pericardium ; 
on each side the lungs are seen ; above, the large vessels are seen springing from it. In 
order to see all this the front of the chest is represented as having been removed. 



tween the lungs, and is covered in front by the breast-bone 
(Fig. 54). It projects beyond the breast-bone on each side, but 



THE BLOOD AND THE CIRCULATION. 



107 



more to the left than to the right. If the hand be placed upon 
the front of the chest on the left side the beat of the heart can 
be felt. This corresponds to the position of the pointed end of 
the heart. If the ear be placed over this spot the sound made 
by the beating of the heart can be heard. 

215. Form of the Heart.— The heart is shaped like acone, 
with the wide part above and the point below. It measures 
five inches from one end to the other. It is hollow (Figs. 56 
and 57), and its walls are formed of muscle-tissue. 

216. The Pericardium. — The heart is surrounded by a sac, 
called the pericardium, mean- 
ing around the heart. Between 
this sac and the heart is a 
space in which a little fluid is 
found. 

217. Cavities of the 
Heart. — The heart is hollow, 
so as to have spaces through 
which the blood can flow. It 
has four such spaces. If we 
look at the heart from the out- 
side, we can first divide it into 
two halves, a left and a right. 
The right and the left sides of 
the heart are separated by a 
groove which runs from the 
wide part of the heart above 
to the point below. Then 
there is a horizontal groove, 
which runs across this vertical 
one and divides each side into 
two smaller parts, an upper 
and a lower. If we examine 
the interior of the heart we find four spaces. The partitions 
which separate these spaces are placed within, exactly where 




Fig. 55. — The Heart and the Large Vessels 
Given off from it. 



108 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 




Fig. 56.— On t line 
Sketch Showing the 
Arrangement of the 
Cavities of the Heart. 
A, Right Auricle; B, 
Left Auricle; C, Right 
Ventricle ; D, Left 
Ventricle. 



the grooves are found on the outside. So that each side of the 
heart has two spaces, an upper and a lower (Figs. 56 and 57). 
The upper spaces are called auricles, and the 
lower ventricles. Consequently, there is a 
right auricle and a left auricle, and a right 
ventricle and a left ventricle. The ventricles 
are much larger than the auricles. The wall 
of the heart is much thicker on the left side 
than it is on the right. 

218. Function of the Heart. — The heart 
serves to pump the blood into the blood-ves- 
sels with such force that it flows all through 
the body. The walls of the heart are made of 
muscle, and this muscle is constantly contract- 
ing, and each time it contracts we say it beats. 
When it does this the whole heart becomes 
smaller, and its cavities become smaller, and thus the blood is 
forced out. After this the heart expands again, its auricles and 
ventricles become wider, and the blood flows into them from 
the veins until the heart becomes filled. These actions of the 
heart are being continually repeated. 

219. Frequency of the Heart- beats. —In the grown per- 
son, the heart beats about seventy times a minute. In the 
child, it beats eighty or more. In the old person it may only 
beat sixty a minute. When sick with fever, the heart works 
more rapidly than in health, and then often beats over a hun- 
dred a minute. 

220. Course of the Blood. — When the blood leaves the 
heart it passes from the right side of the heart to the lungs, 
thence it returns to the left side of the heart, thence it passes 
into the arteries all through the body, and thence it returns 
through the veins to the right side of the heart (Fig. 58). The 
way in which the blood circulates and its course were discov- 
ered in 1618, by an Englishman, named Harvey. It was a won- 
derful discovery. Before Harvey's time nothing was known 



THE BLOOD AND THE CIRCULATION. 



109 



about the way in which the blood flows. The ancients imagined 
that the arteries contain air. 




Fig. 57.— The Heart (the Front has Been Removed), Showing the Interior. 



221. The Circulation through the Lungs.— All the 

blood passes from the veins into the right side of the heart, 
first into the upper space (auricle), and thence into the lower 
space (ventricle). When these two become full of blood the 
heart contracts and squeezes out the blood into a large artery 
(the pulmonary artery), which carries it to the lungs. Here 
the blood passes into smaller and smaller arteries, and, finally, 



110 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



into the very finest tubes, which we call the capillaries (from 
a Latin word meaning a hair, because they are so very 
small). 

222. While the blood flows through these capillaries of the 
lung, it meets the air taken in when we inhale : and from this 





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Fig. 58.— Diagram Showing the Courf 



of the Blood Through the Heart, Lungs, and Body 
in General. 



air it absorbs the oxygen, and gives to it the poisonous carbonic 
acid gas. Thus in passing through the lungs the blood has 
gained oxygen and lost the poisonous gas; and in doing this it 
changes from the dark red color it had before to a bright red 
color ; it is now purified. The capillaries soon join to form 



THE BLOOD AND THE CIRCULATION. Ill 

larger and larger tubes, arid these unite to form several large 
blood-vessels, which carry the purified blood back to the heart. 
But this time it passes to the left side of the heart, first through 
the left auricle and then through the left ventricle. When 
enough blood has flowed into the heart, it contracts and 
squeezes it out into a very large blood-vessel (the aorta), which 
carries it to the tissues in the different parts of the body. 

223 All this is shown very well in diagram in Fig. 58. 




Fig. 59. — The Valves of the Heart, and Between the Heart and the Large Vessels which 

Leave It. 



Starting above, we see the heart ; the shaded part to the left 
representing the right side. The impure blood passes hence 
to the lungs, gradually becoming purified and brighter as 
it passes through this organ. From the lungs it is seen 
to pass in its bright color to the left side of the heart 
(which is the portion of the heart unshaded on the diagram). 
Hence it passes along, as the arrow indicates, to the different 
parts of the body, called on the diagram the system. Pass- 
ing through the system and through the abdominal organs, 



112 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

as shown in the diagram, the blood gradually becomes darker, 
and is shown to be carried by the large veins back again into 
the right side of the heart, the point at which we began to 
trace it. 

224 Valves of the Heart. — The valves of the heart resem- 
ble lids which are placed between the different spaces in the 
heart. They allow the blood to flow one way, but when it at- 
tempts to return in the opposite direction, they close up and 
prevent it. Fig. 59 shows them closed, thus shutting off and 
separating the different cavities of the heart. There are also 
similar valves placed .between the heart and the large vessels 
which leave it. It will readily be seen how important it is that 
such a valve should exist between the left ventricle and the 
large artery which distributes the blood to the different parts 
of the body, the aorta j this valve prevents the blood from flow- 
in o- back into the heart after it has been forced into the aorta. 



THE BLOOD-VESSELS. 

225. Those blood-vessels which take the purified blood from 
the heart and distribute it to all parts of the body are called 
arteries. The blood-vessels which return the used-up blood 
from the tissues to the heart are called veins. Between the 
smallest arteries and the smallest veins are the very finest 
blood-vessels, which are called capillaries. So that the blood, 
after being purified, passes through arteries, then capillaries, 
then veins. 

226. The Arteries. — The large artery which leaves the left 
side of the heart, the aorta, soon divides and subdivides, and 
these branches pass in many different directions, constantly giv- 
ing off other and smaller branches. A tree forms a very good 
example of how the arteries run in the body ; the large trunk 
of the tree corresponds to the large artery which leaves the 
heart, and the branches correspond to the branches of these 
arteries. 



THE BLOOD AND THE CIRCULATION. 113 

227. The Pulse. — When you are sick, and the doctor is 
called, one of the first things he does is to feel your pulse. He 
will put his finger upon your wrist and he will take out his 
watch. Why does he do this? He is counting your pulse. 
If you put your finger upon your own wrist, in front, on the 
side on which the thumb is, you will feel something beat- 
ing. This is an artery, and the beating you feel is your 
pulse. Every time the heart beats the arteries beat, and this 
gives what is called the pulse. This will be understood if it 
be remembered that-every time the heart contracts it pumps 
blood into the arteries, and every time another heartful of blood 
is forced into the arteries, being elastic, they expand and grow 
wider. It is this expansion which is felt with your finger, and 
which is called the pulse. When the doctor counts the pulse, 
he can tell how slowly or how rapidly the heart is beating ; for 
the pulse is the same in number as the heart-beats. The rea- 
son we usually take the pulse at the wrist is because it is most 
convenient ; but there is a pulse in every artery of any size in 
the whole body. You can feel one at your temples, one at the 
side of your neck, and in many other places. 

228. The Capillaries. — These are the very smallest blood- 
vessels, and they connect the arteries with the veins. We find 
the capillaries almost everywhere. They are so small that we 
cannot see them without the use of the microscope. If you 
scratch yourself and a little blood comes, this is from some of 
the capillaries, not from an artery or vein ; for if an artery or 
vein is injured it is more serious. It is while the blood is pass- 
ing through the capillaries from the arteries to the veins, that 
the tissues take from it the oxygen and give up to it the poi- 
sonous carbonic acid gas. And after this change has taken 
place, the color of the blood has changed from the bright red 
of the purified blood in the arteries to the dark red of the im- 
pure blood in the veins. 

229. The Veins. — After the blood has passed through the 
different tissues by means of the capillaries these unite to form 



114 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the smallest veins, and many of these join to form larger ones, 
until finally we have a single large vein, just as we had a sin- 
gle large artery. But there is this difference : The artery 
started from the heart and went to the tissues ; the veins 
start in the tissues and gradually join into a large one which 
goes to the heart. The arteries, too, contained bright-red, 
pure blood; the veins are filled with dark-red or purple, im- 
pure blood. 

230. Valves of the Veins. — There is still another differ- 
ence between veins and arteries : Veins have valves (Fig. 60). 

In the arteries the blood has no 
difficulty in going anywhere, 
even up-hill, because the heart 
pumps it along with consider- 
able force. But there is nothing 
of this sort behind the blood in 
the veins, for after the blood has 
travelled through the capillaries 
it has lost most of the force 
given it by the heart. It would 
therefore be impossible for the 
blood to flow up-hill in the veins, 
as, for instance, in the legs, if 
there were not some arrange- 
ment for this purpose. This 

Fig. 60.— A Pair of Valves in One of the . . 

Veins. They are open ; the direction of the arrangement COnSlStS 111 having 
flow of blood is indicated by the arrow. , ._,. „„, , . , ,. ,, 

valves (Fig. 60) which allow the 
blood to flow toward the heart, but close up, and thus prevent 
it from going in the opposite direction. 

231. Rapidity of the Circulation of the Blood.— The 
blood flows through its vessels very quickly, and it takes about 
half a minute for it to pass from the heart through the lungs, 
all through the body and back again to the heart. How many 
blood-vessels must it pass through in this short time ! 

232. Fainting. — When a person becomes pale and would 




THE BLOOD AND THE CIRCULATION". 



115 



fall if he did not hold on to something, we say he has fainted. 
This often happens after he has been sick and tries to walk 
before he is strong enough. The proper thing to do for such a 
person is to lay him down perfectly flat. There should be no 
pillow underneath the head. If possible, the head should be 
even lower than the rest of the body so that the blood may run 
into the head and fill the blood-vessels of the brain ; for the 
usual reason for the fainting is that the heart becomes weak and 




Fig. 61. — Method of Controlling Bleeding from a Large Wound. 



has not sufficient force to send enough blood to the brain. It 
is also important that no crowd should gather around the person, 
so that he can get all the air possible. The extremities should 
be stroked or rubbed toward the trunk, so as to facilitate the 
flow of blood. 

233. Bleeding. — If we hurt ourselves in any way and the 
bleeding is slight, it will usually stop of itself or after we ap- 
ply a little court-plaster. But suppose we receive a deep cut 
and the blood flows freely and we cannot stop it, what shall 



116 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



we do until the doctor arrives ? We should press upon the in- 
jured jytxvtjust above the cut, or tie a string around it instead 
of pressing with the finger. For instance, if it is the tip of the 
finger which is bleeding very much, we can tie a string around 
the finger an inch or so above the cut and this will stop the 
bleeding. If it is a larger part, as the arm or the forearm, 
tie a handkerchief around the limb above the injury and 
tighten this by means of a stick put under the handkerchief, 
and twist until it is very tight (Fig. 61). Another name for 
bleeding is hemorrhage. 

234. How to have a Good Circulation. — If we wish to 
be in good health, the circulation must be good and brisk. If 
the circulation be sluggish, we are apt to suffer in all parts of 
the body, because no part gets as much blood as it should. With 
a poor circulation the feet are apt to be cold in winter, the per- 
son catches cold easily, he is quickly chilled, he may have head- 
ache, and he is not in the best of health. If we want good 
health, our circulation must be good. 

235. Exercise is the great medicine for a good circulation. 
Any good form of exercise will answer and exercise in the open 
air is the best, because while we are making our blood go 
faster we are also getting more oxygen to the tissues and build- 
ing them up more quickly. Too much exercise, making one 
very tired, or too severe exercise, such as lifting too heavy 
weights, is injurious, because it tires out the heart and makes 
it weak. And if the exercise be much too severe there is even 
danger of bursting a small blood-vessel, though this does not 
happen often. 

236. Effects of Alcohol upon the Heart and the Cir- 
culation. — Alcoholic drink passes into the blood and irritates 
the* heart, and as a result the heart may become too large. It 
might be thought that there would be no objection to having 
the heart too large, but this is not so. For when the heart is 
not of the right size it does not act properly and sickness re- 
sults. The heart of a drunkard often contains a large amount 



THE BLOOD AND THE CIRCULATION. 117 

of fat, which weakens it and it then has not power enough to force 
the blood into the arteries properly, and the different parts of 
the body receive too little blood and become pale and thin. 

237. You may have noticed the flushed face which some peo- 
ple have after drinking. This is because the alcohol drives the 
blood into the blood-vessels of the skin and this becomes warm ; 
but it takes blood from other parts which are more important, 
and these suffer. 

238. The arteries of the confirmed drunkard may become so 
changed as to be brittle. When this change takes place in the 
arteries of the brain they are liable to rupture. This is called 
apoplexy and it often causes the person to fall down dead. Of 
course apoplexy may occur in persons who are not drunkards, 
but it does occur often in drunkards. 

239. Effects of Tobacco upon the Heart and the Cir- 
culation. — The use of tobacco very often affects the heart and 
causes it to throb so that the person feels it and is very much 
annoyed by it. This is called palpitation of the heart. It often 
causes the heart to beat too quickly and then too slowly ; some- 
times too strongly and then too weakly. All these effects are 
so common that such an irregular heart due to tobacco is recog- 
nized by doctors as tobacco heart. Of course, the circulation 
cannot be carried on properly if the heart acts so irregularly. 

THE LYMPHATICS. 

240. Besides the blood-vessels there are other small tubes, 
in which there flows a colorless fluid, looking like water, which 
is called lymph, and these tubes are therefore called lymphatics. 
They are shown in Fig. 62. They differ from the blood-vessels 
in not containing blood ; another difference is that all the lym- 
phatics run toward the heart. 

241. The lymphatics begin by the very smallest tubes, as 
small or smaller than the very finest capillaries. They then 
join together and form larger vessels, and finally they form two 



118 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

large tubes which open into the large veins in the neck (Fig. 
62). 

242. The lymphatics help the veins in returning the used-up 
fluids of the tissues to the heart. We have already learnt that 




Fig. 62.— The Lymphatics and Lacteals. 



fresh, bright blood is brought to the tissues by the arteries, 
and that it circulates through the capillaries of the tissues. 
After the tissues have removed the nutritious portions, the 
used-up fluid is returned to the heart, partly by the veins and 
partly by the lymphatics. 

243. In studying digestion we found that there are certain 



THE BLOOD AND THE CIRCULATION. 119 

vessels in the abdomen which collect the nutritious juices from 
the stomach and intestines and convey them to the blood. 
These are called lacteals, and they are merely a part of the 
lymphatics. 

SYNOPSIS. 
The Blood : 

1. Importance — ' Life's fluid ; ' death when one-third is lost. 

2. Appearance — Thin, watery fluid ; red color, bright or dark. 

3. Composition : 

(1.) Globules : 

a. Ked — Flat, edge thicker than centre, circular in 
man and many animals ; oval and spot in centre in 
birds, reptiles, and fishes ; serve to carry the oxygen 
to the tissues; very numerous. 

b. White — Larger, dotted ; much less numerous. 
(2). Plasma — The fluid of the blood serves to carry the 

poisonous carbonic acid gas from the tissues to the lungs. 

4. Difference in Arteries and Veins : 

(1.) In arteries— Bright red ; contains more oxygen and 
less carbonic acid gas ; cooler ; purer. 

(2.) In veins — Dark red ; contains less oxygen and more 
carbonic acid gas ; warmer ; more impure. 

5. Clotting : 

(1.) Occurrence — When removed from or change in the 
blood-vessels. 

(2.) Products— Clot and serum. 
(3.) Value — Serves to stop bleeding. 
The Heart : 

1. Situation — Between the lungs, behind the breast-bone. 

2. Form — Cone-shaped, pointed end downward ; hollow. 

3. Covering — Sac called the pericardium. 

4. Structure — Muscle-tissue ; a horizontal and a vertical 
groove divides it into two upper and two lower portions, a left 
and a right half. 

5. Cavities — Four: right auricle, right ventricle, left auricle, 
left ventricle. 

6. Function — To pump the blood into the lungs and all parts 
of the body through the arteries. 



120 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

7. Frequency of Beats — In adults, about seventy times per 
minute ; in children, more ; in the aged, less ; in fevers, more. 

8. Valves — To separate the different cavities, when necessary, 
and to prevent the return of blood pumped into the aorta. 

The Circulation — discovered by Harvey in 1618 : 

1. From right auricle to 

2. Eight ventricle, then through pulmonary artery to 

3. Lungs ; here the blood meets the air and is purified, tak- 
ing up oxygen and losing the poisonous carbonic acid gas. 
From the lungs it returns to 

4. Left auricle, then to 

5. Left ventricle ; then it is forced into 

6. The aorta, and then through the branches of this into 

7. The arteries, carrying it to different parts of the body ; 
from these it passes into 

8. The capillaries, which join to form 

9. Veins, and these gradually grow larger, and finally empty 
into a very large one which enters the right auricle of the 
heart. 

10. Rapidity — It takes about half a minute for the blood to 
pass from the heart through the lungs and the system back to 
the heart again. 

The Arteries : 

1. Function — To carry pure, bright blood to the tissues. 

2. Origin — From the aorta, which springs from the heart. 

3. Branches — Constantly become smaller. 

4. Pulse — Owing to the contraction of the heart. 

5. Direction of Flow — From the heart to the tissues. 
The Veins : 

1. Function—To carry impure, dark blood from the tissues 
to the heart. 

2. Origin— From the capillaries, smaller ones gradually unit- 
ing to form larger ones. 

3. Branches — Gradually becoming' larger. 

4. No pulse. 

5. Direction of Flow — from the tissues toward the heart. 

6. Valves — To aid the flow of the blood toward the heart. 
The Capillaries : 

1. Connect arteries and veins. 



THE BLOOD AND THE CIRCULATION. 121 

2. Allow the tissues to abstract oxygen and nutritious mat- 
ters and to add carbonic acid gas and used-up fluids. 

3. Very small, can only be seen by microscope. 
Accidents to and Care of Circulation : 

1. Fainting — Due to scarcity of blood in brain ; lay person 
horizontal, with head low; plenty of air; rub extremities toward 
the trunk. 

2. Bleeding : 

a. If slight will stop by itself, or after use of court- 
plaster. 

b. If severe, press upon the injured part just above the 
cut, or tie something around it here. 

3. Good Circulation necessary to good health. 

4. Necessity of proper exercise to keep up a good circulation. 

5. Effects of Alcohol upon the Heart and Circulation : 

a. Enlarges heart. 

b. Weakens it. 

c. Makes heart fatty. 

d. Flushed face. 

e. Changes arteries. 

/. Apoplexy, bursting of one of arteries of brain. 

6. Effects of Tobacco upon the Heart and Circulation : 

a. Causes heart to beat too rapidly or .too slowly. 

b. Causes heart to beat too weakly or too strongly. 

c. Causes heart to beat irregularly. 
The Lymphatics : 

1. Description — Small tubes containing a colorless fluid called 
" lymph." 

2. Differ from blood-vessels in not containing blood, and in 
that they all run toward the heart. 

3. Begin by very smallest tubes, which by joining together 
form larger ones. 

4. End by two large tubes, which empty into the large veins 
of the neck. 

5. Function, to help the veins in returning the used-up fluids 
of the tissues to the heart, and also to convey nutritious fluids 
from the intestines to the blood-vessels by means of the 

6. Lacteals — A part of the lymphatics. 



122 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



QUESTIONS. 

1. What is meant by the words ' life's fluid ? ' 2. What happens 
if the body loses a large amount of blood ? 3. What does blood look 
like ? 4. Why does blood look red ? 5. What difference is there in 
the appearance of the blood in arteries and of that in veins ? 6. Of 
what two parts is blood composed ? 7. Are the blood-globules very 
abundant ? 8. What is a microscope ? 9. What is it used for ? 10. 
What do you see when you look at a drop of blood under the micro- 
scope ? 11. Are a'iy of the blood-globules white ? 12. What is the 
color of the blood of other animals than man ? 13. How do the 
red blood-globules in birds and fishes differ from those of human 
blood? 14. What is the use of the red blood-globules? 15. Of 
what gases is the air made up principally ? 16. Which is the more 
useful gas ? 17. What happens to the air when we take it into our 
lungs? 18. What part of the blood takes oxygen from the air?. 19. 
What do the red blood-globules do with this oxygen ? 20. What do 
the tissues do with it? 21. Of what use is the fluid part of the 
blood ? 22. Wliat is carbonic acid gas ? 23. Is it harmless or poi- 
sonous ? 24. Where is it sometimes found outside of the body ? 25. 
How can we tell that no poisonous gas exists in cellars or at the bot- 
tom of old wells ? 26. What part of the blood takes up this poison- 
ous gas from the tissues ? 27. What does the blood do with this 
poisonous gas ? 28. What becomes of this poisonous gas in the 
lungs ? 29. What is the difference in color, heat, and purity of the 
blood in veins and of that in arteries ? 30. What happens if blood 
is taken from the blood-vessels and allowed to stand in the air? 31. 
What is this thickening called ? 32. What do we see when we ex- 
amine clotted blood under the microscope ? 33. Of what use is this 
clotting of the blood ? 34. What would happen when we cut our- 
selves if the blood did not clot? 35. What is the best way of seeing 
the blood in motion ? 36. What do we see when we examine the 
circulation of the blood through the thin part of the frog's foot ? 
37. What is the most important organ in the body ? 38. What is the 
shape of the heart ? 39. What surrounds the heart ? 40. About how 
long is the heart ? 41. Of what kind of tissue are the walls of the 
heart formed? 42. Where is the heart ? 43. Where can you feel the 
heart beat ? 44. If you put your ear over this spot, what do you hear ? 



THE BLOOD AND THE CIRCULATION. 123 

45. Is the heart solid or hollow ? 46. How many spaces are there in 
the heart ? 47. How is the heart divided ? 48. How are the sides 
of the heart divided ? 49. Y/hat are the upper spaces called ? 50. 
What are the lower spaces called ? 51. Which are the larger ? 52. 
What is the use of the heart ? 53. What does the heart do when it 
beats ? 54. How often does the heart of a grown man beat in a min- 
ute ? 55. How often does the heart of a child beat per minute ? 
56. How often does the heart of an old man beat per minute ? 57. 
How does the heart beat when we have fever? 58. Describe the 
course which the blood takes. 59. Where does the blood pass to 
from the right side of the heart ? 60. Where from the lungs ? 61. 
Where from the left side of the heart ? 62. Where from the arteries? 
63. How is the blood returned to the heart from the different parts 
of the body ? 64. W T ho discovered the circulation of the blood and 
when ? 65. How does the blood get from the right side of the heart 
into the lungs ? 66. After the large artery carries it to the lung, 
where does it pass to? 67. What is a capillary? 68. What hap- 
pens to the blood when it is passing through the capillaries of the 
lung ? 69. How does it change its appearance while passing through 
the capillaries of the lungs ? 70. Where does the blood pass after 
it has been purified by the lungs ? 71. Where does the purified 
blood pass to after it reaches the heart ? 72. What are the valves of 
the heart ? 73. What is their use ? 74. What three kinds of blood- 
vessels are there? 75. What is an artery? 76. What is a vein? 
77. What is a capillary? 78. Do arteries branch? 79. What is 
meant by " the pulse ? " 80. How can we feel the pulse ? 81. How 
is the pulse produced ? 82. Where do we usually take the pulse, and 
why ? 83. What sets of blood-vessels are connected by the capil- 
laries ? 84. What change takes place in the blood while it is pass- 
ing through the capillaries? 85. What differences are there between 
the vein and the artery? 86. What have the veins which the arteries 
do not have? 87. Of what use are these valves? 88. How long 
does it take the blood to travel through the entire body? 89. What 
is fainting ? 90. What should you do when a person has fainted ? 
91. Why should the head be low? 92. What should we do for 
slight bleeding ? 93. What should we do for serious bleeding which 
will not stop ? 94. What is apt to result if our circulation is slug- 
gish ? 95. What effect has exercise upon the circulation ? 96. What 
effect has too much or too violent exercise ? 97. What effect has 



124 

alcohol on the heart ? 98. What effect has alcohol on the arteries ? 
99. What is apoplexy? 100. What effect has tobacco upon the heart? 
101. What other set of tubes is there in the body besides the arte- 
ries ? 102. What are the lymphatics? 103. Of what use are the 
lymphatics ? 104. What is that portion of the lymphatics which we 
find in the abdomen called? 105. Into what do the lymphatics 
finally empty ? 



CHAPTER VIII. 
THE OEGANS OF VOICE AND BEEATHING. 

244. Another name for breathing is respiring, and hence the 
act of breathing is called respiration. When air is taken into 
the lungs we breathe in or mspire ; when the air passes out 
again, we breathe out or Exspire. 

245. Course of the Inspired Air.— When we inspire, 
the air first passes through the nose, then into the throat, next 
into the sound-producing organ in the neck, the larynx, then 
it passes through a tube running down the front of the neck, 
called the trachea or windpipe, which leads to the lungs. 

246. Each one of these parts will require special study. The 
nose will be left until the study of the sense of smell is taken 
up. The throat has already been discussed in the chapter on 
digestion (Chapter VI.). 

THE ORGAN OF VOICE-THE LARYNX. 

247. The organ which produces sound is called the larynx. 

248. Form and Situation of the Larynx.— The larynx is 
a triangular box (Figs. 63 and 69) the walls of which are formed 
of gristle, or cartilage. It is placed at the upper and front part 
of the neck, and can readily be felt as a hard prominence just 
below the chin. 

249. Parts of the Larynx. — The larynx is formed of sev- 
eral pieces of cartilage joined together. The principal part is 
formed by a large triangular piece which is prominent and 
pointed in front, and can be felt beneath the skin. This 



126 



ANATOMY, 



pointed portion is called Adam's apple, and is larger in men 
than in women, and in some persons it stands out very mucli. 




Fig. 63.— The Larynx, the Trachea or Windpipe, and the Bronchi. 

Just above this triangular cartilage of the larynx, and covering 
up its upper opening somewhat, is another piece of cartilage, 



THE ORGANS OF VOICE AND BREATHING. 127 

called the epiglottis. Below the triangular cartilage is a circu- 
lar piece of cartilage which resembles a seal-ring in shape. 
These three pieces of cartilage, the triangular, the circular, and 
the epiglottis, form the main part of the larynx, though there 
are a few smaller pieces. 

250. Epiglottis. — This is the name given to the piece of 
cartilage, shaped like a leaf, which covers over the top of the 
larynx when we swallow. Usually it stands up straight, but in 
swallowing it is pressed down over the top of the larynx, and 
then the food slides over it into the gullet. If it be remem- 
bered that the larynx is placed- in front, and that the food must 
pass across it (Fig. 67), it will be seen how important such an 
arrangement is ; but as will soon be explained, there is an- 
other way in which the food is prevented from going into the 
larynx and windpipe. 

251. The Vocal Cords. — If we look into the larynx, we 
shall find that there is a shelf projecting on each side (Figs. 64, 
65, and 66) and that these two shelves can be moved ; some- 
times they move toward the middle and meet each other, at 
other times they separate, and then there is a large space be- 
tween them. These are called the vocal cords, because they 
produce the voice-sounds by their motion. 

252. Protecting the Windpipe.— The vocal cords are 
found at the upper part of the larynx ; when they come to- 
gether tightly, they close the larynx completely, so that noth- 
ing can pass into it. This is what they do whenever any food 
or solid body tries to get into the larynx or windpipe. It will 
be seen how necessary this is, for otherwise we should always be 
in danger of being choked. Sometimes the food is swallowed 
unexpectedly, and the vocal cords forget to close ; then we say 
the food has gone down the wrong ivay. This is very distress- 
ing, causing coughing until the*piece of food is dislodged. In 
speaking or laughing during meals, care should be taken that 
the mouth be not full, otherwise this accident may happen. 

253. The Vocal Cords in Breathing. — When we inspire, 



128 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



the vocal cords separate widely, so as to let the air pass readily 
into the windpipe and into our lungs (Fig. 64). When the air 
passes out {expiration), the vocal cords again come together, but 




Fig. 06. 

Figs. 64, 65, and 66.— Showing the Position of the Vocal Cords in Breathing and in Using 
the Voice. In Fig. 64 the cords are widely separated, as they are in inspiration; in Fig. 
65 the cords are slightly separated, as they are in expiration; in Fig. 66 the cords are 
brought together closely, as they are when sounds are produced. 



not tightly, there being still some space left between the two 
(Fig. 65). 

254. How Sounds are Produced. — Previous to making 
a sound we usually take a deep breath. Then this air is blown 
out again, and as it passes through the larynx, between the 
vocal cords, it makes these vibrate, and through the rrpid mo- 



THE ORGANS OF VOICE AND BREATHING. 129 

tion of the vocal cords, sound is produced. There are many 
differences in the quality of the human voice, being- coarse in 
some, sweet in others, high in some, low in others. Then there 
are other peculiarities of the voice, by which we recognize our 
friends by hearing them speak. 

255. It depends very much upon how the vocal cords are 
placed what kind of sound is produced. If the vocal cords 
are brought closely together and are made very tight the 
sound will be high. If you could look into the larynx of a lady 
with a soprano voice, while she is singing, you would find 
the vocal cords very close together ; if, on the contrary, the 
sound is produced while the cords are further apart and less 
tense, the sound will be low, like that of a bass voice. 

256. Speaking. — Although sound is produced in the larynx, 
it is changed by other parts, principally the throat, the mouth, 
the tongue, and the lips. These change the sound so that 
words are spoken. With the vocal cords alone we could make 
sounds as in singing ; but to speak, we must change these 
sounds by means of the parts already mentioned. For in- 
stance, in pronouncing the word paper, the manner in which 
the lips come together will be noticed ; if the word law be 
pronounced, the tongue will touch the top of the mouth. 

THE TRACHEA, OR WINDPIPE. 

257. Situation and Form. — If the finger be passed along 
the front of the neck, from the larynx downward, a hard tube 
can be felt and traced down to the top of the breast-bone ; and 
then it can no longer be felt, for it passes behind this bone into 
the chest. This hollow tube is called the windpipe, or trachea 
(Fig. 63). It serves to conduct the air to the lungs, after it has 
passed through the nostrils, nasal passages, throat, and larynx. 

258. The Air-passage and the Food-passage.— The 
existence of another tube running along the middle of the neck 
— the oesophagus or gullet — has already been mentioned in the 



130 AX ATOMY, PHYSIOLOGY, AND HYGIENE. 



chapter on Digestion. Its purpose is to carry the food to 
the stomach after it has been chewed in the mouth and 

swallowed. The windpipe is 
placed in front of the gullet 
(Fig. 67) ; and both of these 
tubes pass into the chest. The 
windpipe then passes to the 
lungs. The gullet passes 
through an opening in the dia- 
phragm and connects with the 
stomach in the abdomen. 

259. Rings of the Wind- 
pipe. — The windpipe is 
formed of a large number of 
rings of gristle, joined together 
by a thin membrane (Fig. 63). 

260. Branching of the 
Windpipe. — After having 
passed into the chest for a 
short distance, the windpipe 

divides into two smaller tubes (Figs. 63 and 69). These 
branches are called the bronchi, there being two of them, a 
right and a left bronchus. Each carries the air from the wind- 
pipe to the corresponding lung, the right bronchial tube natu- 
rally passing to the right lung, and the left to the other 
side. 




Fig. (57.— The Air-passage and the Food- 
passage. The heavy line indicates the course 
of the food through month and gullet ; the 
dotted line shows the course of air through 
nostril into pharynx, and then into the lar- 
ynx and trachea, which are placed in front of 
the gullet. 



THE LUNGS. 



261. The lung are the organs with which we breathe. There 
is (Figs. 68 and 69) a right lung and a left lung. Between these 
two the heart is placed (Fig. 68). The lungs and the heart fill 
up the entire space in the chest. 

262. Shape of the Lungs. — Each lung is shaped some- 
what like a cone, with the apex above and the base below (Fig. 



THE ORGANS OF VOICE AND BREATHING. 



131 



69). The lungs are very light and contain a great deal of air, 
and float when placed on water. Even after squeezing out all 
the air we can, there will still be a considerable quantity re- 
maining in the lung. 

263. Structure of the Lungs.— If we cut into the lungs, 
we find they are formed of a large number of tubes and 




Fig. 68. — The Heart and Lungs. On each side the lungs are seen ; in the centre is the 
heart ; above are the windpipe and the large blood-vessels passing to and from the heart. 



spaces containing air. After entering the lungs, each bron- 
chus divides again and again (Fig. 69), each branch, known 
as a bronchial tube, becoming smaller, until finally the 
branches of each bronchial tube have become so small that 
they can no longer be seen without the microscope (Fig. 
70, a). 



132 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 




Flu. 69.— The Larynx, Trachea, Right and Left Bronchus, and the Lungs. The latter have 
been cut open to show the method of division and subdivision of the bronchi. 



264. The Air.Ve si c I e s.— The 

smallest branch of a bronchus (Fig. 
70, a) swells so as to end in a lit- 
tle bag containing air, called an air- 
space (Fig. 70, b). The walls of these 
air- spaces are again subdivided so 
as to form a large number of small 
sacs called air- vehicles. The walls of 
these air-vesicles are very thin and 
contain many blood-vessels. From 
this description it will be seen that 
the lungs really consist of a great 
collection of small sacs or spaces filled 
with air. 




Fio. 70.— The Air-vesicles, a, 
The smallest branch of the sub- 
divisions of a bronchial tube : b, 
the dilated pas-age or air-space, 
into which this expands ; c, the 
smallest spaces, air-vesicle*. 



THE ORGANS OF VOICE AND BREATHING. 133 

265. The Pleura. — Upon their surface the lungs are cov- 
ered with a sheet of smooth membrane, called the pleura, which 
also lines the inner surface of the chest. This smooth mem- 
brane allows the lungs to rub against the wall of the chest 
without pain or friction. The pleura resembles the peritoneum 
of the abdomen and serves a similar purpose. 

266. Breathing is Involuntary.— Like the beating of the 
heart, breathing takes place without the use of our will-power. 
It continues whether we are awake or asleep, and even when 
we are unconscious. It is possible to breathe faster than 
usual for a little while, or to hold the breath for a very short 
period, but these are merely temporary changes which cannot 
be continued, for breathing is not under the control of the 
will. 

267. Movements of the Chest in Breathing. — In in- 
spiration air is taken in which passes to the lungs and expands 
them. Watching the chest while this is taking place, it is 
found that the ribs rise and that the chest becomes wider. In 
expiration, the air is allowed to pass from the lungs, these be- 
coming smaller ; the ribs fall and the chest again becomes nar- 
rower. When the lungs are filled with air, they press down 
the diaphragm ; and this then crowds down upon the organs 
contained in the abdomen, which are pushed out; hence the 
bulging of the abdomen in inspiration. 

268. Mouth-breathing. — In breathing, the air should be 
drawn through the nose and not through the mouth. Many 
children breathe through the mouth — an injurious practice 
which results in keeping the mouth open constantly, giving 
rise to a stupid expression of the face and allowing the air to 
reach the lungs in an improperly warmed and impure condi- 
tion. 

269. Frequency of Breathing. — Usually we breathe about 
twenty times a minute. Young children breathe oftener. After 
exercise, we breathe oftener than twenty times per minute. 
When asleep, we breathe less frequently. 



134 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

270. Changes which Breathing Produces in the 
Blood and Tissues. — It has already been stated that the ob- 
ject of breathing is to purify the blood. How this is done has 
also been explained. But the subject is so important that it 
will be well to review it briefly. The air passes into the air- 
spaces of the lungs. In the thin walls of these air-spaces there 
is a large number of very small capillaries. In this way the 
blood in the capillaries is separated from the air by very thin 
tissue only, and gases can pass from the air to the blood and 
from the blood to the air very readily. In breathing, the blood 
takes oxygen from the air, and in exchange it gives it the poi- 
sonous carbonic acid gas, moisture, warmth, and a second poi- 
sonous gas which will be described shortly. 

271. Changes Produced in the Air by Breathing. — 
While the air passes through the lungs it has oxygen taken from 
it — this is the first change. The second change is that it re- 
ceives some of the poisonous carbonic acid gas from the blood. 
Third, it takes moisture from the blood. If you breathe upon 
the window-pane you can easily see this moisture; and in 
winter when it is cold you can notice the moisture in the air 
which we expire, because it becomes visible as soon as it meets 
the cold air. Fourth, the air which we exhale is ivarmer than 
that which we inhale, because it has taken some of the heat 
from the blood. 

272. Finally, the air takes from the blood a certain poisonous 
gas which has a disagreeable smell. The exact nature of this 
unnamed gas is not known, but it is thought to be a mixture of 
many gases. It is known by its smell. If you come from the 
open air into a crowded room you find it disagreeable to breathe 
for a little while, because the air does not seem fresh ; and you 
call it close, and if it is very bad you say it is foul. It is this 
bad-smelling gas which gives this odor. It is fortunate that 
this exceedingly poisonous gas has a bad smell, for otherwise 
we should not know that the air was no longer fresh and needed 
changing. If we stay in such a close room for a little while, we 



THE ORGANS OF VOICE AND BREATHING. 135 

no longer notice the smell, because we have become accustomed 
to it. 

273. Effects of Impure Air. — Much time spent in close 
rooms produces a sleepy, dull, and tired feeling ; the complexion 
suffers and we no longer look so bright as we did. The blood 
cannot be purified in such bad air. In this way all the tissues 
of the body become pale and weak, and the organs no longer 
work as they should. 

274. Purification of the Air. — If the air is constantly 
being made impure by our breathing, it would seem quite 
natural to ask : Why is it that the air does not become so 
impure after a while that we cannot live in it ? This would re- 
sult if God had not provided two great purifiers — sunlight and 
plants. These are the great natural purifiers and change the bad 
air, making it as good as it was before. You have no doubt 
noticed how stale it smells in all dark places, such as cellars. 
This is because the sunlight never enters to purify the air. 

275. The way in which the plants purify the air is still more 
wonderful ; they make use of the poisonous gases as their 

food. Carbonic acid gas is necessary for plants to live and 
grow. Let us stop to consider how plants live and grow : 

276. How Plants Live and Grow. — Plants breathe in 
poUonous gases from the air and breathe out pure oxygen. Be- 
sides the poisonous carbonic acid gas which they take from the 
air, they also absorb moisture and salts from the ground. 
From all these plants form their stems and leaves, and they 
grow until we could hardly believe that the big tree has grown 
from a small plant with no other nourishment than what has 
just been mentioned. In order to do this, plants must have 
sunlight— they will not grow in the dark. So that what is poi- 
sonous to the animal is food to the plant. And in this way pure 
oxygen is returned to the air and the poisonous carbonic acid 
gas is gotten rid of. 

277. Ventilation. — Ventilation means allowing impure air 
to escape from our rooms and letting fresh air takes its place. 






136 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Tins is very necessary. We have already spoken of the effects 
of impure air. If a man were locked in a room and everything 
were tightly closed so that no fresh air could enter, no matter 
how much food and drink he had, he would soon die, because 
his breathing would be constantly making the air of the room 
more and more impure, and finally he would die from want of 
pure air. 

278. In the summer it is quite easy to ventilate our rooms, 
for all we need to do is to open the windows wide and the 
fresh air will stream in and the impure air escape at the same 
time. But in the winter it is more difficult ; for the outside 
air, while it is fresh and pure, is also cold ; and if we opened 
the windows very wide we should feel cold. It is fortunate 
that our windows are not, as a rule, very tight fitting ; hence 
more or less air gets in through the cracks. But it is well to 
draw down the window a little from the top, for the foul air is 
lighter than the fresh air and is always found near the ceiling 
of the room. 

279. Another very good way of ventilating a room is to push 
up the lower window about six inches and to fasten a piece of 
board in front of the open space which you make in this way. 
Or instead of a board a piece of canvas will be better yet, and 
it can be made to look nice by painting or embroidering on it. 
In this w 7 ay the fresh air will come in through the canvas be- 
low, and the foul air will go out in the opening between the 
upper and lower portions of the window, as is show in Fig. 
71. Certain methods of heating rooms are also valuable as 
means of ventilating them. The open-grate fire is one of the 
best means of supplying warmth, because it furnishes such 
a ready escape for the impure air, which passes up the chim- 
ney. 

280. In ventilating rooms it must be remembered that there 
should be no draughts of air upon the persons in the room, for 
otherwise they will catch cold. And also that a room cannot 
be healthy if no sunlight ever enters it. In some of our houses 






THE ORGANS OF VOICE AND BREATHING. 137 

nowadays, and especially in what we call flats, many of the 
rooms are dark and never have any sunlight, and must be 




Pig. 71.— A Rearly Method of Ventilating Rooms. The arrows above indicate the escape 
of the impure air ; those below, the entrance of fresh air. 



unhealthy, as the air in them can never be so pure as in light 
rooms. 



138 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



281. Effect of Tight Clothing upon Breathing.— 

Tight clothing presses upon the chest, and does not allow the 
lungs to expand as they should ; in this way not enough air 
can enter the lungs and the blood suffers, and from this also 
the rest of the body. Besides, if children dress so tightly 
about the chest, it will keep the chest from getting its proper 




Fig. 72.— A Deformed Chest, the Result of too Tight Clothing. Compare with the natural chest 
shown in Chapter II., Fig. 18. The dotted line indicates the position of the diaphragm. 



shape and size (Fig. 72). "We should try to have as broad a 
chest as possible, and should always remember to throw our 
shoulders back, and to sit and stand erect. 

282. Effects of Tobacco Smoke upon the Lungs and 
Throat. — Tobacco smoke is irritating to the lungs of many 
people, and makes them cough. The throat also suffers, and 
becomes red and sore. Such a throat is called by the doctor 
smoker's sore throat. 



THE ORGANS OF VOICE AND BREATHING. 139 



SYNOPSIS. 

The Organ of Voice — The Larynx : 

1. Form — Triangular box. 

2. Structure — Walls formed of cartilage. 

3. Situation — Upper and front part of neck, just below chin. 

4. Function : 

a. Passage of air to windpipe and lungs. 

b. Production of sound. 

5. Parts : 

a. Triangular piece (including Adam's apple). 

b. Circular piece. 

c. Epiglottis. 

d. Vocal Cords : 

(1.) Protect windpipe. 
(2.) Move in respiration. 

(3. ) Produce the voice-sounds by their vibration 
The Organs of Breathing : 

1. Larynx. 

2. Trachea or windpipe. 

3. Eight and left bronchus. 

4. Lungs. 
Trachea : 

1. Situation — Along front of neck in middle line. 

2. Form — Cylindrical tube. 

3. Structure — Kings of cartilage joined together by mem- 
brane. 

4. Function — Conveys air from larynx to lungs. 

5. Branches — Right and left bronchus. 
The Lungs : 

1. Situation— The cavity of the chest, on each side of the 
heart. 

2. Form — Cone-shaped, with apex above. 

3. Function — To purify the blood by allowing it to be 
brought in close contact with the air. 

4. Divisions — Right and left lung. 

5. Structure : 

a. Bronchial tubes. 



140 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

b. Air-spaces. 

c. Air-vesicles. 

d. Pleura, covering outside. 
Breathing : 

1. Is involuntary. 

2. Accompanied by certain movements of chest : 

a. In inspiration, chest becomes wider and ribs rise. 

b. In expiration, chest becomes narrower and ribs fall. 

3. Frequency — About twenty per minute ; more frequently 
in young children and after exercise. 

4. Changes produced in blood : 

a. Gains oxygen and becomes brighter. 

b. Loses carbonic acid gas, other poisonous gas, moist- 
ure, and heat. 

5. Changes produced in air : 

a. Loses oxygen. 

b. Has added : 

(1.) Carbonic acid gas. 

(2.) Poisonous ill-smelling gas. 

(3.) Moisture. 

(4.) Warmth. 

6. Effects of impure air : 

a. Poor health. 

b. Sleepy, dull, and tired feeling. 

7. Effects of bad habits : 

a. Mouth-breathing ; stupid expression ; air improperly 
warmed and cleansed. 

b. Tight clothing about chest ; deformed chest. 

c. Tobacco smoke ; cough ; sore throat. 
Purification of the air : 

1. Natural : 

a. Sunlight. 

b. Plants, by using the carbonic acid gas as part of their 
food and giving back oxygen to the air. 

2. Artificial — affecting dwellings ; ventilation. 






THE ORGANS OF VOICE AND BREATHING. 141 



QUESTIONS. 

1. What is the meaning of the word respiration? 2. What is 
the definition of to inspire ? 3. What is the definition of to ex- 
pire ? 4. Through what different parts does the air pass before 
it reaches the lungs ? 5. What is the organ of voice called ? 6. 
Where is the larynx ? 7. What is its shape ? 8. How is it formed ? 
9. What is Adam's apple? 10. What is the epiglottis? 11. Of 
what use is the epiglottis? 12. What are the vocal cords? 13. 
How do they protect the larynx and the windpipe ? 14. How do we 
prevent food from going the wrong way ? 15. How do the vocal 
cords move in breathing ? 16.. How is sound produced ? 17. What 
makes the difference in the kind of sound produced ? 18. In what 
position are the vocal cords in singing high notes ? 19. In what 
position in breathing? 20. What other parts change the sound in 
speaking ? 21. Could we speak with the larynx alone ? 22. How 
can you prove that the lips and the tongue take part in speaking ? 
23. Where is the windpipe ? 24. What is another name for it ? 
25. Where does it lead to ? 26. What tube runs along together 
with the windpipe ? 27. Which is in front, the windpipe or the gul- 
let? 28. How is the windpipe formed? 29. Wheje does it end 
and what becomes of it? 30. What are the bronchi, and where do 
they go to ? 31. What are the lungs ? 32. Where are they ? 33. 
How many are there ? 34. What is the shape of each ? 35. Are 
they light or heavy ? 36. Why are they so light ? 37. How are the 
lungs formed? 38. What are the air-spaces? 39. What are the 
lungs covered by on the outside ? 40. Do we use our will-power in 
breathing? 41. Can we stop breathing when we want to? 42. 
How do we breathe ? 43. What change do we see when we look at 
the chest while we are breathing? 44. What change if we look at 
the abdomen ? 45. Should we breathe through the mouth or 
through the nose ? 46. How often per minute do we usually 
breathe? 47. What difference is there when we exercise? 48. 
When we are asleep ? 49. What changes does breathing produce 
in- the blood? 50. Where and how do these changes occur? 51. 
What changes are produced in the air by breathing ? 52. What is 
taken from the air? 53. What is given to it ? 54. What poisonous 
gases are added to the air by breathing ? 55. What makes rooms 



142 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

smell close and foul when many people are in them and they are 
not properly aired ? 56. What are the effects of impure air ? 57. 
How is the air purified ? 58. What are the two great purifiers of 
nature ? 59. How do plants purify the air ? 60. What does the 
food of plants consist of ? 61. Can plants thrive without sunlight ? 
62. What is ventilation? 63. Could we live in a room if the air 
were not changed? 64. What is a good method of ventilating 
rooms in winter? 65. In what part of the room do we find most 
of the impure air ? 66. Why are cold draughts undesirable ? 67. 
What effect has sunlight upon the air of a room? 68. Can a room 
into which the sun never shines be healthy ? 69. What effect has 
tight clothing around the chest upon breathing ? 70. What effect 
has tobacco-smoke upon the lungs? 71. What effect has it upon 
the throat ? 



CHAPTER IX. 

THE HEAT OF THE BODY. 

283. Have you ever stopped to think how it is that on the 
coldest day in winter our .bodies remain warm, even though 
we go out into the open air ? It may be necessary to have a 
big fire in our rooms, but still our blood remains just as warm 
as in summer. You may say it is due to the clothing we wear, 
but this is not so. For if you took a cold stone and wrapped 
ever so much clothing around it, you could not warm it. Our 
clothes keep in the heat of the body, but they cannot produce 
any. 

284. The Body may be Compared to a Stove.— We 
can compare the human body to a stove, for there is some re- 
semblance in the manner in which heat is produced. The food 
which we take in by the stomach and the air which we breathe 
combine to form the fuel, just as coal and wood form the fuel 
in the stove. This human fuel is then received by the organs 
of digestion, and changed and liquefied, so that it can be used 
by the various parts of the body. The blood distributes the 
fluid nourishment to the tissues of the body, and also serves 
to relieve these tissues of the poisonous carbonic acid gas, and 
to supply them with oxygen which it has absorbed while pass- 
ing through the lungs. As the tissues of the body are used up 
in performing the work required of them, they are constantly 
being built up again by the nourishing materials which the 
blood conveys to them. 

285. Combustion. — This process of building up the various 
parts of the body by the nutritious portions of the food, changed 



144 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

to a fluid form by the organs of digestion, is followed by a con- 
sumption, or using-up, of the tissues when we use them in any 
way — in other words, when we work. This is called combustion, 
and means a slow burning, and it is accomplished by means of 
the oxygen which the blood carries to the tissues. 

286. What Results from the Burning of Fuel— Work. 
— If we recall the resemblance of the human body to a stove, 
and the similarity of our food to the fuel, it will be instructive 
to ascertain what becomes of the fuel consumed in an ordinary 
fire. Take a locomotive, for example. Its fuel consists of coal, 
which, in burning, combines with the oxygen of the air, thus 
producing combustion. As a result of this combustion, heat 
is produced, which changes the water in the boiler into steam. 
The steam turns the wheels of the locomotive and furnishes 
the power which draws the cars, and enables us to travel many 
hundred miles a day. 

287. Another Result of the Burning of Fuel— Ref- 
use. — As has just been explained, one result of the burning 
of fuel in the locomotive is steam, this combustion taking place 
with the aid of the air. If there is no access of air there can 
be no combustion. Besides steam there is also produced refuse 
— ashes and smoke. These are of no value, and hence they are 
correctly called refuse, and allowed to escape, the smoke passing 
into the air and the ashes thrown away. What w 7 as w r anted from 
the fuel was the steam ; this does the work, whether it moves 
a locomotive or a steamboat, or lifts an elevator, or pumps 
up water ; and all these are merely examples of different kinds 
of work. Fuel, then, consumed with the aid of the oxygen of 
the air, has resulted in work, which is of the greatest value to 
us ; and in smoke and aslies, which are refuse, and which we 
throw away. 

288. What Results from the Combustion of Our 
Food. — If, now, we examine what becomes of the food which 
is consumed by our tissues, both that which we take in by the 
stomach, and the oxygen which the blood takes from the air, 



THE HEAT OF THE BODY. 145 

we find that the same things are produced, namely, heat and 
work, which are of value to us, and refuse materials, which are 
of no use to us, and which are removed from the body. It has 
already been explained how the food is changed and then car- 
ried to the tissues by the blood, and also how the oxygen of 
the air is carried to the tissues. Both of these are fuel, and 
they unite with the tissues ; the oxygen unites with the tissues 
and consumes them, and then the new food builds them up 
again. It may be asked, Why must the tissues constantly 
be used up and then restored ? The answer is, Because we are 
constantly doing work and require heat ; and to get these, the 
tissues must be consumed in our body, just as wood and coal 
are in the locomotive. 

289. Casting off the Refuse Materials from the Body. 
— The refuse materials, which are no longer of any use, and 
which would be harmful if retained in the body, may be com- 
pared to the smoke and the ashes which escape from the loco- 
motive. The organs which serve to remove them from the 
body are the skin, the lungs, the kidneys, and the intestines. 
The skin removes certain poisonous gases, and also certain 
other materials in the perspiration — hence the necessity of 
keeping the pores open. The lungs, as has just been ex- 
plained, remove carbonic acid gas and other poisonous gases 
in the expired air. The kidneys remove impurities in liquid 
form. The intestines remove the solid refuse. 

290. Food and Oxygen Produce Heat and Work. — 
It does not require much study to appreciate how much work 
the body is constantly doing. Even when asleep the body is 
doing work. The heart is working faithfully, beating to sup- 
ply all parts of the body with life's fluid, the blood ; the chest 
is rising and falling and the lungs expanding to take in air ; 
and there are many other examples of work, of constant work. 
When a man is deep in thought, it might be considered that 
he is idle and resting, but this would be incorrect. Such a 
man is working very hard with his brain, and such work is 



146 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

as tiring as working with the hands. Other examples of work 
we see around us every day — the men digging, paving the 
streets, and building the houses. When hard work is required 
more food is necessary than when persons are idle. 

291. Warm-blooded and Cold-blooded Animals.— If 
you touch a stone in the street it will be cold in winter, but 
warm in summer if the sun has been shining upon it. But 
though it may feel warm, it has no heat of its own, and is 
simply warm or cold according as the air around it is warm or 
cold. If you put it in a fire it will become hot, but if taken 
out again it becomes as cold as the bodies around it. This is 
the case with all bodies which have no life. But with animals 
it is different ; they have heat of their own, and it does not 
matter whether the air around them is cold or warm, their 
blood will be about the same. Animals can be divided into 
two classes. One class, the fishes, have cold blood ; you will 
remember how cold and clammy a fish feels. Fishes belong 
to the cold-blooded animals. Most animals, however, have warm 
blood, and hence are called loarm-blooded animals. Most of the 
animals we see are of this class. Birds have especially warm 
blood. 

292. Heat of the Human Body.— The heat of the human 
body is about 98 degrees as measured with the thermometer. 
All of you have probably seen a thermometer. It is a long, 
hollow tube of glass, containing a silvery fluid called quicksilver. 
Heat makes the quicksilver rise, and the more heat the higher 
it rises ; so that we tell how hot anything is by the height to 
which the fluid in the thermometer rises, there being numbers 
attached to the frame of the instrument to express the heat. 
Ninety-eight degrees expresses the heat of our blood, and hence 
this is called blood-heit. On a very warm day in summer you 
may read about the thermometer having risen to blood-heat ; 
this means 98 degrees. 

293. The skin is never so warm as the blood. In winter the 
skin, especially of the hands, may be quite cold, and yet the 



THE HEAT OF THE BODY. 147 

blood-heat remains the same. On the other hand, our skin 
may be very warm in summer, and still the heat of the blood 
does not rise. So that the blood and the interior of the body 
have the same heat in summer as in winter, namely, 98 de- 
grees. 

294. Heat of the Body in Sickness.— When sick with 
fever, the blood becomes hotter ; and if this increase of heat is 
more than a few degrees, it is very dangerous. 

295. Regulation of the Body Heat. — In summer, when 
it is warm, there does not need to be so much heat produced in 
the body, and we naturally take less food, and wear lighter cloth- 
ing, and do not work so hard as in the cold months. In winter, 
on account of the coldness in the air, we must have an extra 
supply of body heat, which we produce by eating more, by 
wearing heavier clothing, and by doing more work. In winter 
we should take more exercise than at any other time of the 
year. Nature usually gives us a better appetite in winter than 
in summer, and we usually eat more meat than when the 
weather is warm. 

296. There is another way in which we increase the warmth 
of the body in winter, and that is by wearing warmer clothing. 
But it has just been stated that clothes do not produce heat; 
then why do we wear thicker and warmer clothes in winter than 
in summer ? This statement is true, clothes do not produce heat, 
but they prevent the warmth from leaving the body too quickly. 
In winter the air is very cold, and the heat of the body would 
pass into the air very soon, to prevent which we put on warm 
clothing. 

297. Warm Clothing. — Woollen clothing is the warmest. 
In winter it is well to wear flannel next to the skin. In sum- 
mer linen clothing is the coolest. Black clothes are warmer 
than white ones because they absorb more external heat. This 
can easily be shown in the following way : If you take two 
pieces of cloth of the same kind and size, and place them on 
the snow, that under the black cloth will be melted before that 



148 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

under the white one. This is the reason for wearing dark 
clothing in winter and light colors in summer. 

298. How to Keep Warm in Winter In winter we de- 
pend upon exercise, additional food, and warmer clothing to 
keep us warm. And all three of these must be combined if we 
want to feel comfortable. You have seen car-drivers slapping 
their arms about on a cold day. This gives them exercise and 
makes them warm ; it makes the warm blood circulate faster, 
and this brings heat to the tissues. If you stand still on a 
wintry day the feet soon become cold. This is very unhealthy, 
and is a sign that you should exercise in order to get more 
blood back into the feet. If we go out on a cold day before 
breakfast we feel very chilly ; and everyone knows how much 
better he is able to stand the cold after having had a warm 
meal. 

299. How to Keep Cool in Summer. — In summer we 
should eat less meat and less food than in winter. Usually our 
appetite is not so good in summer as it is in winter, and natu- 
rally, therefore, we take less food, and we should wear light 
clothing. Everything we do during the warm parts of the sum- 
mer days we should do slowly and should not hurry. We should 
not w r alk much in the sun without being shaded. 

300. How the Body is Kept Cool in Summer.— It 
would seem difficult to prevent the body from being over- 
heated in summer when the air around us is so warm ; and you 
might wonder, too, why it is that the blood of a locomotive en- 
gineer, or of a cook, who is in front of a hot fire all day long, is 
no warmer than that of j>ersons who can keep cool. There are 
two ways in which the bodily heat is prevented from rising 
above 98 degrees when persons must be near furnaces and 
fires or are otherwise exposed to the heat. 

301. Both methods depend upon the fact that whenever 
moisture or ivater leaves any surface it makes that surface cold ; 
that is, it takes some of the heat of that surface with it. In 
India, the drinking-water is cooled by placing it in porous clay 



THE HEAT OF THE BODY. 149 

vessels which allow a little of the water to soak through, after 
which it passes off into the air and thus makes the rest of the 
water cool. If you wet your hand and then hold it in the air, 
it feels cold, because the water iu passing into the air takes 
some of the heat of the hand with it. 

302. In this way our blood does not get any warmer in sum- 
mer than in winter. For iu summer more moisture leaves the 
body than in winter. Moisture leaves the body in two ways : 
By the lungs and by the skin. We breathe more rapidly in 
summer than in winter, especially if it is very warm, and in 
this way, more moisture is- given off to the air from the blood 
passing through the lungs. Then again, the expired air con- 
tains more moisture in summer. 

303. Perspiration. — The moisture which passes off by the 
skin is called perspiration. This is taking place constantly 
through the pores, but in summer so much passes off that it col- 
lects in drops and is then called visible or sensible perspiration, 

304. Ice-water in Summer. — There is no objection to 
ice-water in summer if you do not drink too much, and if } t ou 
take but a little at a time. Some people get into the habit of 
drinking ice-water constantly. This is very unhealthy and will 
make them suffer. But if it be remembered to drink it slowly 
and only a little at a time, it will not usually do any harm. 

305. Sunstroke. — When a person has been in the sun a 
long time, the heat of the blood may become so great, or the 
effect of this heat upon the nerves so serious, that it makes him 
dangerously sick ; this is called sunstroke. It is a very danger- 
ous condition. If you have to walk much in the sun, you 
should stop and go into the shade and rest as soon as you feel 
the least faint or dizzy. 

306. Effects of Cold. — If we are in the cold a long time, it 
sometimes happens that defreeze the vose, ears, toes, or fingers. 
When this occurs, the frozen part of the body becomes pale or 
purple. At first it becomes painful, but when really frozen 
it has no feeling at all. The reason these parts of the body 



150 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

freeze is because the blood does not flow in them as it should ; 
there is too little blood in them, and so there is too little heat 
to keep off the cold. When the ears or the nose begin to 
smart they are beginning to feel the effects of the cold, and we 
should rub them so as to bring the blood back. When we are 
very cold and have frozen a part of the body, we should not go 
near the fire at once ; the change of temperature would be too 
sudden and the frozen part might die. We should give the 
frozen part a thorough rubbing. 



SYNOPSIS. 

Combustion — The slow consumption of the tissues : 

a. Kequires food and oxygen. 

b. Produces : 

1. Life. 

2. Growth. 

3. Work and heat. 
Refuse of the Body : 

a. Gaseous, given off by : 

1. Lungs — expiration. 

2. Skin. 

b. Liquid, given off by kidneys. 

c. Solid, given off by intestines. 
Heat of Animals : 

a. Warm-blooded animals. 

b. Cold-blooded animals. 
Heat of the Human Body : 

1. About 98° in health in the interior. 

2. Colder on the surface of the skin, depending upon tin 
warmth of the air. May be slightly warmer in summer. 

3. Higher in sickness (fever). 

4. Regulated by : 

(1.) Amount and kind of food. 

(2.) Amount and kind of clothing. 

(3.) Amount of exercise. 

(4.) Perspiration. 



THE HEAT OF THE BODY. 151 

To Keep Warm in Winter : 

1. Much clothing, especially woollen ; flannel next to skin. 

2. Much food, especially meat. 

3. Much exercise. 

To Keep Cool in Summer : 

1. Light clothing, especially linen. 

2. Less food, and less meat. 

3. Less exercise. 

The Control of Bodily Heat in Summer — By increased escape of 
moisture by lungs and by skin. 

Undesirable Effects of Heat and Cold : 

1. Sunstroke. 

2. Freezing parts. 

3. Bad effects of too much ice-water. 



QUESTIONS. 

1. What effect has our clothing upon the body heat? 2. In 
what way can the body be compared to a stove ? 3. What corre- 
sponds to the fuel of the stove ? 4. What do we call the slow burn- 
ing which takes place in the body ? 5. How does fuel do work in 
the locomotive ? 6. What results from the fuel in a locomotive be- 
sides the steam which does the work ? 7. What results -from the 
combustion of our food ? 8. What does the oxygen of the air do ? 
9. Why are the tissues constantly used up and then restored ? 10. 
What gases are given off from the body ? 11. What is the object of 
taking food into our stomach, and oxygen from the air into our 
blood ? 12. What do these produce ? 13. Is the body ever idle ? 
14. What work does it do even when we are asleep ? 15. Is the 
body doing any work when we think ? 16. Can a hard-working man 
get along on as little food as one who is idle ? 17. Do all animals 
have the same warmth of the blood ? 18. What is meant by a cold- 
blooded animal ? 19. Give an example. 20. What is meant by a 
warm-blooded animal ? 21. Give an example. 22. Have bodies 
without any life in them any heat of their own ? 23. What is the 
heat of the human body ? 24. What is a thermometer ? 25. Is our 
skin warmer or cooler than the rest of our body ? 26. What change 
is there in the heat of the bodv when wo have fever? 27. What do 



152 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

we do in summer so that less bodily heat shall be produced ? 28. 
Do we need more heat or less heat in winter- than in summer ? 
29. How do we produce more heat in winter ? 30. Do clothes pro- 
duce heat? 31. What do they do to the heat? 32. What is the 
warmest kind of clothing ? 33. What is the coolest kind of cloth- 
ing? 34. What color of cloth is the warmer, black or white? 35. 
How can you show this ? 36. What should we do to keep warm in 
winter ? 37. What should we do to keep cool in summer ? 38. How 
is the body kept cool in summer? 39. Does the blood become 
warmer if we stand in front of a fire all day ? 40. What effect is 
produced when moisture passes into the air ? 41. How can you 
show this effect by an example ? 42. In what ways does moisture 
leave the body ? 43. What is perspiration ? 44. How does perspira- 
tion keep the heat of the body from rising ? 45. How can you take 
ice-water in summer without harming you? 46. What is sunstroke? 
47. What should you do to avoid being sunstruck ? 48. What are 
the effects of great cold ? 49. What parts of the body are we most 
apt to freeze? 50. In what way may certain parts of the body 
freeze? 51. How does the nose or ear feel when it is freezing? 52. 
How do they feel when they are frozen ? 53. Should we go near 
the fire immediately when we have frozen a part of the body ? 54. 
What should we do ? 



THE HEAT OF THE BODY. 



153 







Fig. 73-General View of the Nervous System in the Human Being, 



CHAPTER X. 
THE NERVOUS SYSTEM. 

307. Thus far the bony framework of the body and the 
muscles which cover and move the skeleton have been spoken 
of. The food and drink which man should take and what be- 
comes of this have been considered ; also how this food is di- 
gested and taken up by the blood, forming new tissues. The 
heart and the blood-vessels which convey the blood to all parts 
of the body have been described. The lungs and breathing 
and the effects of pure and impure air, have been studied. 
Finally, the necessity of the body's having and keeping a cer- 
tain warmth has been spoken of. 

308. These functions are found in all animals, but they are 
not peculiar to animals for they also exist in plants. The word 
function was defined to be the work which any part of the 
body does. All these different kinds of work that we have 
been studying, and which are necessary for animal life, are also 
found in plants. 

309. Similarity in the Structure of Plants and Ani- 
mals. — The plant has a framework which corresponds to our 
skeleton, though of course it is not made of lime. This can 
often be seen in leaves that have been in water a long time ; the 
soft parts have rotted away, leaving the stems and ribs of the 
leaf, as is shown in Fig. 74. In plants there is a soft, usually 
green matter to clothe this skeleton. Plants take in food and 
drink by their roots and by their leaves. They also breathe 
through pores in their leaves, and take in air and give it up as 
animals do. But from the air they take in the poisonous 



THE NERVOUS SYSTEM. 



155 



gases and give up pure oxygen. This is just the reverse 
of what animals do. It may be well to explain what pores 
are. They are the very small openings in the skin or in the 
coverings of leaves ; and are usually 
too small to be seen without a mi- 
croscope. 

310. Then again plants have sap, 
which serves as their blood. It is 
not of a red color as blood is, but 
like the blood in animals, it car- 
ries the nutritious juices to the 
different parts of the plant. There 
are tubes which carry the sap, 
just as blood-vessels do the blood. 
Finally, plants have a certain 
warmth of their own, just as ani- 
mals have ; not so great as in ani- 
mals, but if many plants are placed 
in a closed room, the air in this 
room after a time becomes com- 
paratively warm. 

311. Absence of Nervous 




Fig. 74.— The Skeleton of a Leaf. 
After long-continued peaking in water, 



System in PlantS.— Thus it Will the soft part of the leaf has been re- 
■J moved, leaving the woody portion 



forming the framework, whicli gives the 
leaf its shape and strength. 



be seen that plants have all the 
parts and the same functions that 
have been described in animals thus far. But now will be 
considered certain parts in animals which plants do not possess, 
the first and most important of which is the Nervous System. 
Let us first see what is meant by the word system. It is a 
collection of tissues of the same kind. So that nervous system 
is a collection of nerves, or in other words, all the nerves of 
the body taken together are called the nervous system ; all 
the arteries taken together would be called the arterial sys- 
tem. All the muscles of the body are called the muscular sys- 
tem. 



156 ANATOMY, PHYSIOLOGY^ AND HYGIENE. 

312. Most Perfect Nervous System in Man. — The 

nervous system is something peculiar to animals and does not 
exist in plants. In animals there is a great difference in regard 
to how perfect this nervous system is. The higher the form of 
the animal, the more perfect is its nervous system. Man being 
the highest form of animal, his nervous system is much more 
developed than in any other animal. In some of the lowest 
animals it is very imperfect indeed. In other functions, such 
as respiration, circulation, and digestion, there are many classes 
of animals which are the equals of man ; but in the development 
of his nervous system man stands far ahead of all others. 

313. Function of the Nervous System. — The nervous 
system gives us information of the condition of the body and 
of ivhat is going on around us, so that we can do what is best 
and avoid danger. It is also the work of the nervous system 
to connect the different organs of the body so that they will work 
in harmony. If it were not for the nervous system we should 
constantly be in danger of losing our lives. It enables us to 
feel, think, see, hear, etc., and in this way we avoid injury. 
When a large number of persons are working separately there 
must always be a head or chief to direct them. Imagine what 
disorder there would be in the class-room if every pupil did as 
he or she wished and there were no teacher. Think of an army 
of soldiers over which there was no general, and every soldier 
did as he wished ; how dreadful the confusion would be ! In 
the same way there would be great disorder among the organs 
of our bodies if there was not something to connect them 
and to direct their work ; this is done through the nervous 
system. 

314. Divisions of the Nervous System.— We can divide 
the nervous system into certain parts, and these parts are all 
connected. We separate them only for the purpose of study. 

315. There is first the brain, the head or chief that superin- 
tends the entire work of the system, just as the superintendent 
of a railroad manages the running of all the trains. The brain 



THE NERVOUS SYSTEM. 157 

is placed in a rounded, bony box made by the bones of the 
skull, called the cranium. 

316. Next there is the spinal cord, which is still very im- 
portant, though not so important as the brain. It is a sort of 
assistant to the brain, relieving it of a good deal of work, and 
also doing some work which the brain does not do. The spinal 
cord runs in the canal or tunnel which is in the back part of 
the spinal vertebrae. 

317. Finally, there are the nerves. These are sent out from 
the brain and from the spinal cord to different parts of the 
body ; and they also run in the opposite direction — from the 
various parts of the body to the brain and spinal cord. They 
are the messengers, or the telegraph wires, so to speak, which 
carry the wishes of the brain to the different parts of the body ; 
and they also carry messages from the different parts of the 
body to the brain. These different parts of the nervous system 
are illustrated in Figs. 73 and 79. 

318. Examples of the Action of the Nervous System. 
— The uses of the nervous system can best be understood by a 
few examples. Suppose a man is walking along the street and 
is about to cross the car-track. His ear hears the jingle of the 
bells and by means of a nerve sends a message to the brain ; 
the brain then sends an order along the nerves of the eyes to 
these organs to look in the direction in which the ear has heard 
the sound and to see whether a car is approaching. The eyes 
obey the orders of the brain and look and see the car very near, 
and also perceive that the person is in danger of being run 
over. They immediately send back word to the brain about 
this danger. Then the brain sends word to the muscles which 
move his legs ; this message is also transmitted by nerves ; it 
tells these muscles to act immediately. The result is that they 
obey ; he quickens his steps and thus escapes the coming- 
car. 

319. Let us take another example. Suppose it is time for 
the noon recess ; you have taken your breakfast early in the 



358 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

morning and have had no food since. The stomach sends a 
message to the brain that it has been empty for some time ; 
and the tissues also send messages by numerous nerves that 
they would like more nourishment since they have exhausted 
all that the blood had to give them. Upon receiving these 
messages, which, in short, mean that you are hungry, the brain 
gives out its orders. It directs the legs to carry you home as 
soon as school is dismissed ; it directs them to take you to 
the dining-room and to seat you at the table ; it directs the 
eyes to look at the food and see whether it is wholesome ; it 
orders the hands to seize knife and fork and to convey food 
to the mouth ; the jaws are directed to chew it, the throat 
to swallow it and the stomach to digest it. All this the brain 
does. 

320. Rapidity of Action of the Nervous System.— It 
has taken a little while to describe these two examples of the 
manner in which the nervous system acts, but it must not be 
imagined from this that so much time is consumed. All these 
messages are sent back and forth with lightning-like rapidity, 
and it takes only a very small part of a second for a message to 
travel from the tip of the finger to the brain and back again. 



THE BRAIN. 

321. Coverings. — The brain is a large, rounded mass of 
soft nervous tissue which is contained in the oval box of bones 
formed by the skull. These flat bones which cover it protect 
it from injury. Besides these, it is covered on the inside of the 
skull by three membranes or sheets of tissue ; and it is therefore 
very well protected. 

322. Size and Weight of the Brain.— The brain is about 
eight inches long. If looked at from above (Fig. 75) it appears 
hemispherical ; if viewed on its under surface (Fig. 76) it is flat. 
It weighs about forty-seven ounces — about three pounds on the 
average. The brain of a man is larger and weighs more than 



THE NERVOUS SYSTEM. 



159 



that of a woman. It was formerly thought that highly educated 
persons had very heavy brains, but this is not so in every case. 
It is true in certain cases, however, for the brain of Daniel 
Webster weighed sixty-three ounces. On the other hand, the 
brain of Gambetta, who was one of the brightest statesmen 




Fig. 75.- The Brain, Upper Surface. 



France ever had, was said to weigh only thirty-five ounces. So 
that there are exceptions to this opinion. However, the brains 
of idiots are always small and light in weight. It will be ex- 
plained further on in what way the brain of a very intelligent 
man differs from that of an idiot. The human brain is heavier 
than that of any other animal except the whale and the ele- 
phant. 



160 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

323. Divisions of the Brain.— The brain is divided into 
three parts : First, the large, round mass called the cerebrum, 
which you see when you look at it from above, and which forms 
about seven-eighths of the entire brain (Figs. 75, 76, 77, and 
79). 




Fig. 76.— The Brain, Lower Surface. 

324. Then beneath the cerebrum, at the back part, is the 
cerebellum, or little brain, a smaller portion, looking like two 
pouches, and forming only one-eighth of the entire brain (Figs. 
76, 77, and 79). 

325. Third, there is the portion, called the medulla, which is 
a sort of bridge between the brain and spinal cord (Figs. 77 
and 79). 



THE NERVOUS SYSTEM. 



161 



326. The Cerebrum. — As already stated, this is the main 
part of the brain. If you look at it from above you will see 
that it dips in along the centre, and you will find this cleft 
to be quite deep, separating the brain into two halves, called 
the hemispheres — a very appropriate name. The surface of the 
cerebrum is very uneven, due to the fact that it is covered by 
a great many winding elevations, between which the surface 




Fig. 17. — The Brain, Looked at from the Side, Showing Very Nicely the Divisions of the 
Brain. The large mass above is the cerebrum ; the smaller portion, below and behind, is 
the cerebellum. From the cerebrum above, a cylindrical portion is seen passing directly 
downward to the end of the illustration below ; this is the medulla. The cerebellum is seen 
to be connected with its upper and back part. 



dips in about an inch. In a person whose brain is very much 
developed and who is very bright, these elevations are very 
winding and complex, and between them the brain matter dips 
in very much ; while in the lower animals the elevations are 
quite straight and simple, and there is very little dipping in 
between them. 

327. Gray and White Parts of the Cerebrum.— On the 
outside the cerebrum is gray, but internally it is white. The 



162 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



gray part consists of cells, that is, small bodies with a Dumber 
of branches given off from them, which connect with the nerve- 
fibres. The interior of the cerebrum is white, and is formed 

by millions of nerve-fibres (Fig. 

78). 

328. The Cerebellum.— 
This, like the cerebrum, is gray 
on the outside and white within. 
It is much smaller than the ce- 
rebrum, and is placed behind 
and below it, being covered up 
by it (Figs. 77 and 79). 

329. The Medulla (Figs. 77 
and 79) serves to connect the 
brain with the spinal cord. It 
is very important. There is one 
part of it to which any injury 
will produce instant death. 

330. The Cranial Nerves. 
— -What is a nerve? A nerve 
is a collection of nerve-fibres 
forming a small cord. These 
nerve-fibres are very small, and 

can be seen only with the microscope. But when a great many 
of them run alongside of each other they are joined into a 
bundle, and this we call a nerve. Some nerves are very large 
and others quite small. At the ends, where they pass to the 
tissues, they are very small indeed. 

331. The brain gives off twelve sets of nerves, and these all 
pass to the tissues of the head and face. They are important, 
for among them are the nerves of smell, taste, sight, and hear- 
ing. There are small holes in the bones of the skull b} r which 
these nerves pass out. It has already been stated that the 
cranium is the bony box in which the brain is contained ; 
hence these nerves are called cranial, because they come from 




Pig. 78.— A Portion of the Cerebrum 
Cut Across. Showing the Gray Border on 
the Outside and the White Matter Within. 



THE NERA'OUS SYSTEM. 163 

this bony box. They are arranged in pairs, one behind the 
other ; on which account they are often called in numerical 
order, first, second, third, etc. 

332. Functions of the Brain. — The brain is the seat of the 
mind, of the will, of thought, of memory, and of intelligence. It 
is through the brain that we are rendered superior to the lower 
animals. The lower animals accomplish different actions 
through what we call instinct, that is, without the action of 
the mind. But we can do many more things than they, and 
more difficult acts, because our brains are more developed. 

333. Let us examine the -work of the brain and see what it 
does for us : In the first place, it is where the will exists ; it is 
where our desires come from. Then as to memory, it is the 
brain which enables us to think about things and to remember 
names, figures, faces, and all other things. Imagine how useful 
this is and how difficult it would be to get along without it ! 
Think also of the wonderful action of the brain when it is pos- 
sible to remember things all our lives ! 

334. The brain gives us reason, so that when we see a thing 
we know what it means and whether it is important or not. It 
gives us judgment which enables us to do the right thing in 
order to accomplish what we want. 

335. Intelligence has its seat in the brain. This prevents 
us from being stupid ; and enables us to understand things and 
to express ourselves just as we wish by language. It enables 
us to see the difference between right and wrong, so as to avoid 
the latter. 

336. Training of the Brain.— Much of our memory and 
intelligence depends upon the way in which our brain is trained. 
If we use our brain a great deal, it will become better than if 
we allow it to remain idle. Many things which we study at 
school are taught us for the purpose of training the brain. We 
should remember that we cannot think of more than one thing 
at a time. When you study your lessons, you should not think 
of play ; and when you play, you should enjoy yourself, and 



164 ANATOMY, PHYSIOLOGY. AND HYGIENE. 




Fig. 79. —The Brain and Spinal Cord, with the Spinal Nerves Issuing from the Latter. 



THE NERVOUS SYSTEM. 



165 



need not think of your studies, 
time for study. 



There is a time for play and a 



THE SPINAL CORD. 



337. The spinal cord is the soft bar of nerve-tissue which 
runs down from the brain through the canal of the backbone. 
In adults it is about as thick as the thumb. Besides being 
protected by bone , it has, like the brain, a covering of three 
membranes. While the spinal cord is not so important a 
part of the nervous system as the brain is, it is still very 
important, especially that part which runs through the neck. 
One sometimes hears of people falling down stairs and break- 
ing their neck. What is meant by this is that this upper 
part of the spinal cord is broken across and death occurs im- 
mediately. 

338. If the spinal cord be sliced crosswise it would be seen 
that although it is white on the outside, it is gray on the in* 
side. This gray matter in the 
interior is arranged in a pe- 
culiar manner, resembling two 
crescents joined together, as is 
shown in Fig. 80. As in the 
brain, this gray part is formed 
of cells, while the white portion 
consists of nerve-fibres. 

339. Spinal Nerves.— The 
nerves which leave the brain are 
called cranial nerves ; and those 
which leave the spinal cord are called, in the same way, spinal 
nerves. There are thirty-one pairs of spinal nerves ; and they 
are connected to the side of the spinal cord in a line. Each 
nerve when it leaves the spinal cord consists of two parts, 
one in front and the other behind ; but these two portions 
soon unite to form a single nerve. 




Fi G . 80.— A Portion of the Spinal Cord 
Cut Across, Showing the Gray Crescents in 
the Interior Surrounded by the White 
Nerve Material. 



166 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



340. Kinds of Nerves. — There are two kinds of nerves — 
the nerves of sensation, and the nerves of motion. The nerves 
of sensation are those which give feeling" to different 
parts of the body and especially to the skin. When 
you cut or burn yourself it is a nerve of sensation 
which carries the message of pain to the brain. 
The nerves of motion are those nerves which go to 
the different muscles and cause them to act when 
the brain wishes it. 

341. Functions of the Spinal Cord.— The 
spinal cord is a sort of agent or assistant to the brain, 
and it also serves to carry the large number of 
nerve-fibres which leave the brain, travel through 
the spinal cord and then to the limbs. But besides 
this, the spinal cord has a very important use. 
When the brain is engaged at something else, the 
spinal cord takes its place, and acts for it if any oc- 
casion arises. 

342. Reflex Action. — This action without the 
Nerve 81 very knowledge of the brain is called reflex action, and 
5ffed y show- ^ * s ^ ne spinal cord which carries it out. Let us 
ing How it is £ a ] ie a f ew examples of reflex action : Suppose vou 

Made up of L *■ *■ - 

Numerous wan t to go to school in the morning. Your brain 

Nerve-fibres. ° ° 

directs the muscles, of your lower limbs to move in 
such a manner that you walk. But after you have started 
walking, you do not need to think about it ; perhaps you reach 
school and have crossed many streets and have turned many 
corners without knowing it. It was the spinal cord which 
looked out for all this. 

343. If a fly alights upon your face, you put up your hand 
to brush it off, without really thinking of it. This is another 
example. 

344. During sleep, reflex action is shown very well. If you 
tickle the feet of anyone who is asleep, he will draw up his 
lower limbs so as to draw them away ; all of which will be done 



THE NERVOUS SYSTEM. 167 

without his waking. It is the spinal cord which looks after this. 
In the same way, if you walk along, thinking of something else, 
and suddenly some one appears before you and makes a motion 
as though to strike you, you will draw up your arm to protect 
yourself before you can realize that anyone is there. If some 
one makes believe striking you in the face, you cannot help 
closing your eyes, and you cannot keep them open even if you 
want to. This is reflex action. It is also reflex action which 
explains how it is that a chicken can run around after its head 
is chopped off. 

345. Sleep. — Sleep is the natural rest of the brain. Just as 
every other part of the body needs rest during each twenty-four 
hours, so does the brain. In fact, many other parts of the body 
can exist longer without rest than can the brain. We may 
rest any other part of the body without sleep ; but the only 
sign that the brain is resting completely, and is not active, is 
sleep. 

346. The Amount of Sleep which is necessary varies 
with different people. Men who think a great deal require 
more than those who do bodily work. The average sleep neces- 
sary for a man is from seven to eight hours. 

347. Children require more Sleep and should have 
nine or ten hours, for while the body is growing rapidly more 
rest is needed. 

348. Uses of Sleep. — During sleep the brain and all other 
parts of the body rest and regain the strength which they have 
lost by the day's work. 

349. Time for Sleep. — Night is the time for sleep. Per- 
sons who work at night and sleep by day are not usually quite 
so bright and healthy as those who sleep during the natural 
time. Young people who dance all night and then sleep by 
day to make up for it, soon look pale and tired out, and often 
weaken their bodies so much that they become sick. The 
proper time for children to go to bed is from eight to nine 
o'clock, and they should then rise at six or seven. 



168 ANATOMY, PHYSIOLOGY, AND HYGIENE 



j lUlUiVUUUl, 



350. Nervousness. — We often hear people say they are 
nervous. By this they mean that their nervous system is out 
of order. They start at the least noise, and become cross and 
irritable, while the rest of the body suffers. Nervousness is 
often due to too little sleep or too much excitement. Very 
often, too, it is due to indigestion, or to coffee, tea, or tobacco, 
or alcoholic drinks. When we are nervous we are apt to do 
things in haste, and are apt to talk in a cross manner and to get 
angry easily. 

351. Wakefulness. — When unable to sleep at night, we are 
said to suffer from sleeplessness or wakefulness. Lying awake 
at night when all is quiet and everyone else is asleep is very 
annoying. Not only does the body remain tired after the day's 
work, but the person becomes worried and cross because he 
cannot sleep. There are, of course, many causes of sleepless- 
ness, but some of the most common are laziness, coffee, tea, and 
tobacco. It is quite natural for us to feel somewhat tired at 
night, and then we have no trouble in falling asleep ; but if we 
are idle all day long, we do not feel tired, and on this account 
we may find it hard to fall asleep. Coffee, tea, and tobacco ex- 
cite the nervous system, and on this account may prevent sleep. 

352. Effects of Alcohol upon the Nervous System.— 
The nervous system has no greater enemy than alcohol. Every 
part of the nervous system — the brain, the spinal cord, and the 
nerves— suffers when a quantity of alcoholic drink is taken. 
The brain becomes affected very soon. If a large quantity is 
taken at one time and the person becomes intoxicated, he be- 
comes stupid in his intelligence, but excited in other ways — he 
sings, or cries, or begins to laugh like a fool, or begins to scold, 
and often fights. He forgets that he is a human being and acts 
like a brute. He is unable to walk straight and staggers along 
in a pitiable way, catching on to lamp-posts or any other place 
for support. The effect upon the nerves is shown by the way 
every part of his body trembles, and by his great unsteadiness. 
A drunken man is a disgusting 1 sight ! If his drunkenness be 



THE NERVOUS SYSTEM. 169 

repeated many times and becomes a habit, the memory begins 
to fail, the person becomes bloated and fat, but very weak, his 
health fails, his hands tremble, his eyes and nose are constantly 
bloodshot, he becomes dirty and careless, and the individual 
changes into a good-for-nothing. 

353. Delirium Tremens. — As a result of drunkenness 
there is often produced a disease of the nerves called delirium 
tremens. This means that the person is out of his mind and 
has trembling of the body. It is a condition which kills many 
men, and which is dangerous to the drunkard, because he gets 
out of his mind and tries to do all sorts of violent things, espe- 
cially to jump out of the window. He imagines that he sees 
animals, such as mice, rats, and snakes, and he thinks these are 
chasing him, and he wants to run away. It is difficult to keep 
him quiet. The whole body trembles from the poisonous ef- 
fects of the alcohol. The heart is often weakened so much 
that the person dies because this organ has become too weak. 

354. Effects of Tobacco upon the Nervous System. — 
This shows itself chiefly by the trembling hands and the ner- 
vousness which we often notice in people who smoke a great 
deal. Many persons, especially young men, cannot smoke at all 
without nervousness. 

355. Effects of Coffee and Tea upon the Nervous 
System. — Coffee and tea excite the nervous system. They 
are often the cause of nervousness and trembling ; also of pal- 
pitation of the heart, which is a form of nervousness. Children 
should not drink coffee or tea, as they do not need any stimu- 
lants. 

356. The Sympathetic System of Nerves. — Besides the 
great nervous system to which this chapter has been devoted, 
there is a smaller collection of nerves, which is known as the 
sympathetic system. Along the front of the backbone are found 
two nerves, with many knob-like enlargements at numerous 
points. This is the central part of the sympathetic system, 
from which the branches of this system are given off. Unlike 



170 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the nerves of the general nervous system, which pass to the 
outside of the body and to parts which are subject to our will, 
the branches of the sympathetic system pass to the internal 
organs which cannot be controlled by our will, and which are 
therefore called involuntary. The sympathetic system serves 
to connect the internal organs so as to make them act in har- 
mony. 

SYNOPSIS. 

The Nervous System : 

1. Present in animals, but not in plants. 

2. Functions : 

a. To give information in regard to the condition of va- 
rious parts of the body. 

b. To give information of what is going on around us, so 
that we can act accordingly, and can avoid danger. 

c. To connect the different organs of the body, so that 
they can act in harmony. 

3. Divisions : 

a. The general nervous system ; nerves passing to ex- 
ternal parts, and those controlled by our will. 

b. The sympathetic nervous system ; main part arranged 
in two chains, with knob-like enlargements along the front 
of the vertebral column ; from these branches are given 
off; branches pass to internal organs which are not under 
control of the will — involuntary. 

The General Nervous System : 
Divisions : 

A. Brain: 

1. Coverings : 

a. Membranes. 

b. Bones forming cranium. 

2. Shape — hemispherical. 

3. Size— about eight inches long. 

4. Weight— a. Average about forty-seven ounces. 

b. Heavier in man than in woman. 

c. Verv light in idiots. 



THE NERVOUS SYSTEM. 171 

d. Weighs more in man than in any other ani- 
mal, except the whale and elephant. 

e. In some cases, weight is proportionate to in- 
telligence. 

5. Gives off the cranial nerves. 

6. Natural rest — Sleep : 

a. Necessary amount varies. 

b. Hard work necessitates more. 

c. Average for man, seven to eight hours. 

d. Children require more, nine to ten hours. 

e. Use, to give body, and especially brain, a 
complete rest. 

/. Proper time, at night. 

g. Disordered sleep— wakefulness — may be due 
to laziness, tea, coffee, or tobacco. 

7. Divisions: 

a. Cerebrum : 

1. Largest part of brain (seven-eighths). 

2. Large, round mass. 

3. Divided into halves, called hemispheres. 

4. Surface uneven, owing to winding eleva- 
tions, between which the surface dips in. 

5. The height of these elevations and de- 
pressions is proportionate to the intelligence. 

6. Exterior gray and formed largely of 
cells. 

7. Interior white, and formed entirely of 
nerve-fibres. 

8. Controls mind, will, thought, memory, 
and intelligence. 

9. Gives reason and judgment, elevating 
man above the lower animals. 

10. Admits of training. 

b. Cerebellum, or little brain. 

1. Much smaller than cerebrum. 

2. Forms one-eighth entire brain. 

3. Forms lower and hind part of brain. 

4. Like cerebrum, is gray on outside and 
white within. 



172 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

c. Medulla: 

1. Connection between brain and spinal cord. 

2. Very important part, since injury to one 
portion causes instant death. 

B. Spinal Cord : 

1. Long bar of nerve-tissue. 

2. Protected by : a, membranes. 

&, bones forming vertebral column. 

3. Interior formed of gray matter, arranged in cres- 
cents, and composed largely of cells. 

4. Outside is white and formed of nerve-fibres. 

5. Gives off the spinal nerves. 

6. Acts as an agent or assistant to the brain. 

7. Controls reflex action — action without the knowl- 
edge of the brain, serving to protect us from injury. 

C. Nerves : 
Divisions : 

1. According to action : a, sensation ; b, motion. 

(1.) Nerves of sensation, carrying impres- 
sions of feeling, such as pain, etc., from the 
surface to the brain and spinal cord. 

(2.) Nerves of motion, carrying messages 
from the brain and spinal cord to the muscles, 
and causing these to act. 

2. According to source : a, cranial ; b, spinal. 

(1.) Cranial nerves, twelve pairs, pass from 
brain, through openings in bone, to various 
parts of the head and neck. 

(2.) Spinal nerves, thirty-one pairs, emerge 
from spinal cord by two roots, which soon join 
together, pass to different parts of the trunk 
and limbs. 
Disorders of the Nervous System, due to : 

1. Coffee and Tea : 

a. Often excite nervousness, trembling, etc. 

b. Children should not be allowed any. 

2. Tobacco — Often causes nervousness, trembling, etc. 

3. Alcoholic Excess : 

a. Great enemy to nervous system. 



THE NERVOUS SYSTEM. 173 

b. Stupefies intelligence. 

c. Excites brain in undesirable ways, such as fighting, 
etc. 

d. Causes trembling and staggering. 

e. Other effects on rest of system. 

/. Delirium tremens— Eesult of drunkenness, person out 

of mind ; great trembling; person violent, often wishing to 

jump from window ; person imagines he sees enemies, mice, 

rats, snakes, etc. ; heart often seriously weakened, and may 

die from this cause. 

The Sympathetic Nervous System — Smaller than general nervous 

system — Central or main part extends along the front of spinal 

column — Branches pass to internal, involuntary organs. 

QUESTIONS. 

1. What different parts are found in plants as well as in animals? 
2. What is the skeleton of a leaf? 3. Do plants take in food and 
drink? 4. How? 5. How do plants breathe ? 6. What difference 
is there in the breathing of plants and of animals ? 7. What are 
pores? 8. What fluid is there in plants corresponding to the blood 
of animals? 9. How is the sap carried along ? 10. Do plants have 
any warmth of their own ? 11. How can you prove this ? 12. What 
part of animals is absent in plants ? 13. What is a system ? 14. Give 
an example. 15. Does the nervous system exist in plants ? 16. In 
what animal is there the highest form of nervous system ? 17. What 
is the function of the nervous system ? 18. What might happen if 
we did not have a nervous system ? 19. Give an example to show 
that there must be a chief to everything where there are many parts. 
20. Into what parts can we divide the nervous system? 21. What is 
the office of the brain ? 22. What of the spinal cord? 23. What of 
the nerves? 21. Give an example of the action of the nervous sys- 
tem. 25. Does it take the nervous system a long time to act ? 26. 
Give an example to show how quickly it acts. 27. Where is the 
brain situated? 28. What protects it? 29. Is it soft or hard? 30. 
What is its form ? 31. What is its size? 32. What is its weight? 
33. Is it heavier in man or in woman ? 31. Does its weight depend 
upon the intelligence of the person? 35. Give examples. 36. What 
can you say about the brains of idiots ? 37. Into what parts can the 
brain be divided ? 38. Where is the cerebrum ? 39. What are the 



174 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

hemispheres ? 40. What can you say about the surface of the cere- 
brum ? 41. What is peculiar about the surface of the cerebrum in very 
intelligent persons ? 42. How is it different in the lower animals ? 
43. What is the color of the cerebrum on the exterior? 44. What is 
the color of the interior ? 45. Of what does the gray matter consist ? 
46. Of what does the white matter consist ? 47. Describe the cere- 
bellum. 48. Describe the medulla. 49. Why is it very important ? 
50. What is a nerve? 51. Where are the cranial nerves ? 52. To 
what are they attached ? 53. Name the functions of the brain. 54. 
What is meant by doing things "by instinct?" 55. Where does 
the will exist ? 56. What is meant by memory ? 57. What is intel- 
ligence ? 58. What is reason? 59. What is judgment? 60. How 
can we train the brain ? 61. What is the spinal cord? 62. How is 
it protected ? 63. What is meant by " breaking the neck ? " 64. 
Of what is the spinal cord formed? 65. How does it look inside ? 
66. What are the spinal nerves ? 67. How many are there ? 68. 
How do they leave the spinal cord ? 69. What two kinds of nerves 
are there? 70. What are the functions of the spinal cord? 71. 
What is reflex action ? 72. Give an example of reflex action. 73. 
Of what use is reflex action? 74. What is sleep? 75. How must 
the brain be rested? 76. What is the average amount of sleep re- 
quired for a man? 77. How much for a child? 78. What are the 
uses of sleep? 79. What is the proper time for sleep ? 80. When 
should children go to bed ? 81. When should they rise ? 82. What 
is nervousness? 83. What is nervousness due to? 84. What is 
wakefulness? 85. What are some of the most common causes ? 86. 
Is it natural for us to feel a little tired at night ? 87. Why can some 
persons who are idle all day long not sleep at night ? 88. How do 
coffee, tea, and tobacco act on the nervous system ? 89. What effect 
has alcohol upon the nervous system ? 90. How is the brain affected 
in drunkenness ? 91. Name some of the disgusting actions of the 
drunkard. 92. How are the nerves affected ? 93. What are the ef- 
fects of repeated drunkenness ? 94. What is delirium tremens ? 95. 
What are the symptoms of delirium tremens? 96. What effect has 
tobacco on the nervous system ? 97. What effect have coffee and 
tea on the nervous system ? 98. What is the sympathetic system of 
nerves? 99. What is the function of the sympathetic system? 
100. What is its arrangement ? 101. To what parts is the sympa- 
thetic system distributed ? 



CHAPTER XI. 

THE SENSES. 

357. There are certain organs in the body which add a great 
deal to our comfort and enjoyment and give us knowledge and 
pleasure. The functions of these organs are called the senses. 
There are five of them. 

1. Touch — The skin. 

2. Taste— The tongue. 

3. Smell — The nose. 

4. Sight— The eye. 

5. Hearing. — The ear. 

358. Special Senses. — They are often called the special 
senses because each one has a special duty to perform and can- 
not be used for anything else ; as, for instance, our eyes can be 
used for seeing only. The skin is the only one of these organs 
which is necessary to life ; and it is an organ of general rather 
than of special sense. 

THE SENSE OF TOUCH— THE SKIN. 

359. Thickness. — The skin forms a soft, elastic layer which 
covers the entire body. It is not of the same thickness in all 
places. It is thick at certain places where the body is very 
much exposed or where there is much friction, as in the palms 
of the hands and the soles of the feet. In other places which 
are more protected, it is quite thin ; as, for instance, the inner 
side of the arm. 

360. Uses of the Skin.— As has already been stated, the 
skin is necessary to life, In certain accidents, in which a per- 



176 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

son has burnt or scalded himself severely, he may die because 
too much of the skin has been lost. There are four principal 
uses of the skin : (1) As a protection to the entire body ; (2) 
as the organ of sensation or feeling ; (3) to throw off water, 
salts, and poisonous matter from the body ; (4) to regulate the 
bodily warmth. 

361. The Skin as the Organ of Sensation or Feeling. 
— The nerves of sensation or feeling end in the skin in little 
knobs, which are the portions with which we feel the different 
sensations, such as heat, cold, smoothness, roughness, pain, etc. 
Some parts of the body are more sensitive than others. This 
is because they have a greater supply of these nerves. These 
same nerves also give rise to pain, which is useful, as it pro- 
tects the body, and tells you when to be careful. If you are 
holding a lighted match in your fingers, you will drop it as 
soon as it burns down to your finger-tips because there is pain. 
If there were no pain to warn you, the ends of the fingers might 
have been burnt of? before you were aware of it. With these 
nerves we are enabled to feel whether anything is smooth or 
rough, sharp or dull, cold or warm, soft or hard. The finger- 
tips are intended as the organs of touch. In the blind, the 
sense of touch becomes very much developed, and such persons 
can be trained to do wonderful things by means of the fingers. 
The books of the blind are printed with letters which are slightly 
raised ; and it is marvellous how quickly they can spell the 
words by means of their fingers. 

362. Throwing off Water, Salts, and Poisonous Mat- 
ters. — This is a very important use of the skin. If an animal 
were to be covered with paint or varnish so as to close all the 
pores, death would result in a short time. 

363. Regulating the Bodily Warmth.— The skin serves 
an important purpose in regulating the bodily warmth. It 
does this by increasing or diminishing the amount of perspira- 
tion, thus cooling the body in summer by permitting free 
perspiration. 



THE SENSES. 



177 




364 Structure of the Skin- — The skin is formed of two 
layers (Fig. 82). The outside layer is called the scarf skin, the 
deeper one the true skin. 

365. The scarf skin is formed 
of a great many scales or flat 
cells covering each other ; and 
these cells are being constantly 
rubbed away and cast off, and are 
then replaced by new ones. In 
taking a bath, for instance, it will 
be noticed that in drying a little 
of the skin comes off. This mate- 
rial is formed of the dead cells 
which are cast off. The scarf 
skin of the scalp is often cast off 
in small scales which we call dan- 
druff. This throwing off of these 
scales from the skin of the body 
takes place all the time and is 
natural. In snakes the scarf 
skin is thrown off in one piece and forms the very pretty tubes 
sometimes found in the fields. 

366. The true skin is the part which contains the blood-ves- 
sels and the nerves ; also the roots of the hair, the perspiration 
tubes, and the oil tubes. If you burn yourself, a blister forms, 
which separates the scarf skin from the true skin ; if you lift 
up the blister, the red part you see underneath is the true 
skin. The true skin is not perfectly smooth, but has a number 
of small projections upon it. But these do not appear on the 
surface of the skin because the cells of the scarf skin fill out 
the uneven places (Fig. 82). 

367. Color of the Skin. — The skin is colored differently 
in different parts of the body. It is darker, for instance, on 
the back of the hand than on the arm. Some persons have very 
light-colored skin and are said to have a fair complexion, and 



Fig. 82,— A Piece of Skin as Seen Under 
the Microscope, d, The layers of flat cells 
forming upper layer of the scarf skin ; c, 
deeper layer of scarf skin ; b, projections 
of true skin. 



178 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

these usually Lave blonde hair. Others have dark complexions 
and usually have hair of a dark shade. In the negro, the skin 
is dark brown. This difference in the color of the skin depends 
upon the amount of coloring matter which is found in the true 
skin. In white people there is very little of this, in the negro 
there is a great deal of it in the form of small dark brown grains. 

368. If you look at the skin of the palms of the hands, espe-* 
cially at the finger tips, you will see fine lines arranged in cir- 
cles. If you examine these with a magnifying glass it will be 
seen that the lines are raised, and it is here that the nerves of 
feeling end in great numbers. 

369. Attachments of the Skin. — Upon examining the 
skin, we find in it, or attached to it, certain parts : Perspira- 
tion tubes, oil tubes, hairs, and, in certain parts, nails. 

370. The Perspiration Tubes. — These are the small tubes 
in the skin, which give -off the perspiration. There are a great 
many of them. Where they open upon the skin there is a 
small space called a pore. There are thousands of these pores 
in the space of every inch of the skin. This shows the necessity 
of keeping the body clean, so that the pores remain open, for 
otherwise the perspiration cannot escape. The perspiration 
tubes open upon the surface of the skin ; below, they com- 
mence by a series of windings in the deeper parts of the skin, 
as is shown in Fig. 83. 

371. The Perspiration. — Perspiration is constantly being- 
given off from the body, day and night. Most of the time, 
especially when the weather is cool, it is invisible, and hence is 
called insensible perspiration. .But if more than the usual 
amount is given off from the skin, the perspiration collects in 
drops and is called sensible perspiration. This occurs in sum- 
mer and at other seasons of the year when we become over- 
heated or work hard. Perspiration consists largely of water ; 
and in the water certain mineral salts and certain poisonous 
matters which it is necessary for the body to cast off- are dis- 
solved. 



THE SENSES. 



179 



372. Uses of the Perspiration. — It has just been stated 
that the perspiration takes from the body water, salts, and poison- 
ous matters. Even when the weather is cold and perspiration 
is insensible, about a pint of water leaves the 
body daily by the skin ; and in summer much 
more than this escapes. This will give an 
idea how many of these perspiration tubes 
there must be and how active they must be. 
Perspiration is also very important because 
it cools off the body, as has already been de- 
scribed in the chapter on The Heat of the 
Body. 

373. The Oil Tubes.— Besides the per- 
spiration tubes, there are others which run 
through the skin and open on or near its sur- 
face, usually where there is hair (Fig. 84). 
These tubes give off a certain oily substance 
which keeps the skin soft and movable, with- 
out which the skin would get dry and cracked. fig. 83.— one of the 

. in* Perspiratory Tubes. 

This oily matter also serves to keep the hair (Greatly magnified.) 
gloss}' and soft ; and we find the greatest num- pass through the en- 
ber of oil tubes where there is hair. It is to skin, through its aif- 
remove the oily matter which has become stale 
that we need soap in washing. Sometimes there is too much 
of this oily matter and then the skin has a greasy look, such as 
we often see on the forehead and nose. Sometimes these oil 
tubes become stopped up by a little dirt ; and as a result the 
oily matter is kept in and we see a black spot on the nose or 
forehead. This is often called a worm, but it is no worm, but 
simply the oily matter which cannot escape because the open- 
ing of its tube has become clogged up. 

374. The Hair. — If a hair be examined it will be found 
that one end is pointed, while the other, which was attached 
to the skin, has a white knob, called its root, and it is through 
this that it is fastened to the skin (Fig. 84). The hair is not 




180 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

solid but is a tube, and has a canal in its centre filled with a 
soft material. Deep in the skin there are small cup-like spaces 
into which the root of the hair fits and is attached. Hair 
differs very much in color, and this is because there is a differ- 
ence in the amount of the coloring substance present in differ- 
ent cases. 

375. The Nails. — At the end of the fingers and toes are 
the nails. They are hard and horny and serve to protect the 
finger tips and give them firmness. In front they have no feel- 
ing and we may cut them without paining us. But further 




Fig. 84.— A Piece of Skin Cat Across to Show the Way in which Hair is Attached to the 
Skin. (Highly magnified.) There is seen to be a depression in the skin into which the 
hair dips. Below, the round, expanded extremity or root of the hair is seen. .Two oil tubes 
are seen opening along the side of the hair near the surface of the skin. 

back they are very firmly attached to the back of the finger 
and here they are very sensitive. 

376. Care of the Skin. — You will now appreciate how im- 
portant the skin is, and why it is necessary to keep it in good 
condition. Cleanliness is next to Godliness is an old saying ; 
if you wish to be healthy you must be clean. Dirt is, as a 
rule, a sign of ignorance ; and those nations are usually the 
dirtiest which are the most backward in civilization. On the 
other hand, the more civilized people are the cleaner do they 
keep themselves* There are few things that cause so much 
disease as uncleanliness and filth. 

377. The Results of Uncleanliness and Filth. — When- 
ever you read of outbreaks of cholera and such diseases you 



THE SENSES. 181 

will always find that they occur in parts of cities which are 
overcrowded and filthy. This was shown in the last outbreak 
of cholera many years ago in New York. It is easy to un- 
derstand why this should be so. The pores of the skin are 
the openings by which the body gets rid of waste materials, 
just as the sewer pipes of a city carry off the refuse. Suppose 
the sewer becomes stopped up in a large city, what trouble it 
causes ! What dirt ! What a stench ! In the same way, 
when we allow the dirt to cover the pores of our skin, the 
poisonous materials cannot escape, and the body suffers. In 
taking proper care of the skin it is necessary to pay attention 
to bathing, to our clothing, to exercise, and to avoid using pow- 
der or any like substance upon the skin. 

378. Bathing. — It is not sufficient to wash the hands and 
face daily ; we should wash off the entire body at least once a 
week. If you shake out some of your underclothing at night, 
you will find a great many small white flakes fall to the ground. 
They represent the uppermost layer of the skin which is con- 
stantly being cast off in these small particles and replaced 
by the deeper layers. The entire body is covered with these 
scales, and it is necessary to remove them often. Some fall off 
b} r themselves, but others must be removed by soap and water. 
Consequently, at least once a week we should take a warm 
bath, and use soap in it, for this removes the stale, oily matter 
also. 

379. Cold Baths. — Besides the warm bath for the sake of 
cleanliness, we should take cold baths, especially in summer, 
because they are refreshing arid strengthening. After taking a 
cold bath it is well to rub the body with a coarse towel so as to 
make the skin glow and tingle. This causes the blood to cir- 
culate faster, and increases our strength and appetite. It is 
injurious to remain in a cold bath until you begin to shiver. 
As soon as you begin to feel chilly you should go out. Many 
persons are harmed by cold bathing because they remain in 
the water for too long a time. Some persons are naturally 



182 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

weak, and when they take a cold bath they are not able to 
withstand its effects, so that even though they rub the body 
afterward they still feel cold and chilly ; which is a sign that 
they are unable to endure cold bathing. Such people should 
be content to simply sponge off the body with cold water, be- 
sides taking a warm bath about once a week for the purpose 
of cleansing the body. Never bathe directly after a meal ; wait 
two or three hours. If you are overheated and perspire freely, 
it is better to wait until you are somewhat cooled off before you 
go into cold water. Always wet the entire head as well as the 
rest of the body when bathing. 

380. The Turkish and the Russian Bath.— Probably 
all of you have heard of the Turkish bath and the Kussian bath. 
In the Turkish bath, the person is kept in a room with very hot 
air until he perspires freely ; he is then scrubbed with soap 
and water ; then he plunges into a cold water bath ; next his 
skin is rubbed and his muscles kneaded by men who are em- 
ployed for this purpose. This causes the blood to flow r 
faster ; then the person rests himself thoroughly before going 
out into the air. The Bicssian bath is similar, the only differ- 
ence being that the room is filled with steam instead of hot 
air, to make the person perspire freely. These baths are good 
for grown people, but are not suitable for children. 

381. Clothing. — In the chapter on The Heat of the Body 
something has already been said about proper clothing, so 
that little need be added here. We should change under- 
clothing frequently. It is a healthy practice to take off all our 
underclothing at night and allow it to hang up and be thor- 
oughly aired before putting on again the next morning. 

382. Exercise helps to keep the skin in good condition by 
making us perspire more freely, and in this way keeping the 
pores open. It also causes the blood to circulate through the 
skin more rapidly, which gives us the delightful feeling of 
warmth after exercising. 

383. Cosmetics. — The use of powders and like substances 



THE SENSES. 



183 



upon the skin is very injurious. These substances, which are 
called cosmetics, stop up the pores and make the skin rough 
and ugly. Besides, many of them are poisonous, and this 
poison may get into the blood through the skin and poison 
the body. Powdering the face is not done by the better class 
of people. 

384. Care of the Hair. — The hair should be combed and 
brushed every morning. Every few weeks it will be necessary 
to wash it with soap and water. The oil tubes of the scalp 
usually supply enough oily matter to keep the hair glossy ; 
hence the practice of putting oil or grease on the hair is not 
only very vulgar and nasty but it is unnecessary. Crimping the 
hair by hot irons destroys the hair and makes it fall out. Hair 
dyes are injurious ; nearly all are made of deadly poisons, which 
may get into the blood and poison the entire body. 

385. Care of the Nails.— The nails should be cut with 
scissors at regular intervals. The 
finger nails should not be bitten 
off. The nails should not be cut 
too close or else the finger tips 
and the ends of the toes will be- 
come SOre. Many persons have Fig. 85,-Proper and Improper Method 

sm . p rnp ~ pq-nppiallv thp hio- top of TrilTimi "£ the Too nails. The figure 
SOie toes, especially me Olg toe, to the left exhibits che proper method— 

Wnnap thov r\n nnf put fhP noil cut off squarely; that to the right, the 

oecause tney cto not cut tne nan improper me thod-cut off round and 

properly. It should be cut close - 

straight across and not rounded and short (Fig. 85). Hangnails 

often result from biting the nails or keeping the fingers in the 

mouth. 




184 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

SYNOPSIS. 

The Skin : 

1. Thickness — Varies in different parts of body. 

2. Uses: 

a. Protection. 

b. Organ of sensation or feeling : 

1. Acuteness varies in different parts of body. 

2. Greatest at finger- tips. 

3. May be developed, as in the blind. 

4. Depends on the nerves of sensation, ending in the 
skin by small knobs. 

c. To throw off water, salts, and poisonous matters from 
the body. 

d. To regulate the bodily warmth. 

3. Structure : 

a. Scarf-skin on the outside. 

b. True skin beneath. 

4. Color: 

a. Varies in different parts of body. 

b. Varies in different races. 

c. Depends on the amount of brown coloring matter ex- 
isting in the true skin. 

5. Attachments : 

a. Perspiration-tubes — Openings called pores ; necessity 
for keeping open ; perspiration, sensible and insensible ; 
removes matters from body and cools body. 

b. Oil-tubes — Keep skin soft and hair glossy and soft ; 
necessity for using soap to remove stale oily matter. 

c. Hair — Eoot and point ; hollow ; color varies ; should 
be combed and brushed daily ; should be washed every few 
weeks ; no oil or dyes. 

d. Nails — Should be cut regularly, not bitten off; cut 
across square. 

6. Care of Skin: 

a. Cleanliness. 

b. Bathing : 

1. Warm bath and soap for cleanliness. 

2. Cold bath, refreshing. 



THE SENSES. 185 

3. Turkish bath. 4. Russian bath. 

5. No cold baths for those too weak to stand them. 

6. No bathing directly after meals. 

7. No bathing when overheated. 

8. Wet head as well as rest of body. 

9. Eub body well with coarse towel after bath. 

c. Clothing — Necessity for changing underclothes fre- 
quently. 

d. Exercise. 

e. Cosmetics — To be avoided. 

QUESTIONS. 

1. Name the special senses. 2. Is the skin of the same thickness 
throughout the body ? 3. At what points is it the thickest ? 4. What 
are the uses of the skin? 5. Is it necessary to life? 6. How is 
this proven? 7. Of what service is pain? 8. Of what use are the 
nerves of feeling? 9. What parts of the body are intended espe- 
cially for feeling ? 10. What is peculiar of the touch 6f the blind ? 
11. What is discharged from the body by means of the skin? 12. 
What effect has the skin upon the bodily warmth ? 13. Is the color 
of the skin always the same ? 14. Upon what does the color of the 
skin in the negro depend ? 15. Of how many layers is the skin 
formed? 16. What are these layers called? 17. Of what is the 
scarf-skin formed ? 18. What becomes of the scales which form 
the scarf-skin? 19. What is dandruff? 20. Describe the true 
skin. 21. How do the two layers of the skin become separated in 
slight burns ? 22. Describe the perspiration tubes. 23. What are 
the pores ? 2i. What is insensible perspiration? 25. What is sensi- 
ble perspiration ? 26. What are the uses of perspiration ? 27. What 
does the perspiration remove from the body? 28. About how much 
perspiration leaves the body every day ? 29. How does perspiration 
cool off the body ? 30. What appearance does the skin of the finger- 
tips present ? 31. What other tubes are there besides the perspira- 
tion-tubes ? 32. Of what use is the material which the oil-tubes pro- 
duce ? 33. What happens when the oil-tubes get stopped up? 34. 
Why does the skin of the nose and forehead sometimes have a 
greasy look ? 35. Describe a hair. 36. How is hair attached to the 
skin? 37. Of what use are the nails? 38. Why is cleanliness so 
very important ? 39. Of what is dirt a sign in regard to civilization ? 



186 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



40. What effect upon the health has filth? 41. Why is filth so bad 
for the health? 42. How often should the entire body be washed? 
43. Why should the entire body be washed frequently with soap and 
warm water? 44. What are the effects of a cold bath? 45. What 
should we do to make the circulation more brisk after a cold bath ? 

46. What is the sign that you have been in a cold bath long enough ? 

47. Is it well to bathe directly after a meal ? 48. What other pre> 
cautions should you take when bathing ? 49. Explain the Turkish 
and the Eussian bath. 50. Should we wear the same underclothing at 
night that we have worn during the day ? 51. How does exercise 
affect the skin ? 52. What are cosmetics ? 53. What effect have 
they upon the skin? 54. What should be done to the hair? 55. 
What can you say about the practice of putting oil or grease upon 
the hair ? 56. What are most hair dyes made of ? 57. How should 
the nails be cut ? 



THE NOSE— THE SENSE OF SMELL. 

386. Functions. — The nose is the organ with which we 
smell. It is also the part through which the air is drawn. The 



Smell 
Mr 



Tood 




Fig. 8G.— Diagram Exhibiting the Channels by which Smell, Air and Food Reach the In- 

terior of the Body. 



lower part of the nose represents a passage for breathing, the 
upper portion is the part devoted to the sense of smell (Fig. 86). 



THE SENSES. 187 

387. The Breathing Channel and the Smelling Chan- 
nel. — When we breathe we draw the air backward through the 
lower part of the nose. This part of the nose runs horizontally 
backward, and behind joins the throat ; so that if a fluid is 
poured into the nose it will run into the throat. When we 
smell, we draw the air upward, because we want the odor to 
ascend to where the nerves of smell are. 

3S8. Parts of the Nose. — The nose is formed of bones 
and gristle. The hard part on the outside, where usually peo- 
ple wear their eyeglasses, is formed of two small bones and is 
called the bridge of the nose-. In looking into the nose we find 
that it is divided into two halves. The openings in front are 
called the nostrils. In the interior of the nose on each side are 
found three shelves of bone covered by a soft membrane ; and 
beneath each shelf is a passage-way which runs from the front 
to the back of the nose. 

389. The Nerves of Smell. — In the membrane which 
covers the two upper shelves just described, are found numer- 
ous nerves, the nerves of smell. By consulting Fig. 87, it will 
be seen that the brain lies immediately above the nose. These 
nerves of smell come in bunches from the brain, and descend 
into the nose. Although we are in the habit of saying that we 
smell with the nose, it would be more correct, strictly speaking, 
to say that we smell with the front part of the brain. The 
nerves of smell merely serve to carry the odors to the brain. 
This is proved by the fact that there is a loss of the sense of 
smell if the front part of the brain be injured or diseased, even 
though the nerves of smell still be present. 

390. The Sense of Smell in the Lower Animals. — 
Many of the lower animals have a much more acute sense of 
smell than man. Dogs and cats, for instance, can smell the 
faintest odors at great distances. . In hunting dogs the sense 
of smell is extraordinarily acute ; they can smell game miles 
away and for this reason are valuable in hunting. This is 
spoken of as scenting the game. Before the civil war, blood- 



188 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

hounds were employed to track runaway slaves, and they were 
able to do this owing to the acuteness of their sense of smell. 

391. Cold in the Head. — Almost everyone has caught cold 
at some time. When we catch cold it may settle in any part of 
the body ; it may attack the lungs, or the stomach, or some 
other organ. When the cold settles in our head we usually 




Fig. 87.— View of the Interior of the Nose, showing the Nerves of Smell Descending: into 
the Nose from the Brain, in the Form of a Bunch. 



feel it principally in the nose and throat. We often get a sore 
throat and our nose feels stopped up so that we cannot smell, 
and we cannot breathe through it, because there is too much 
blood in it. 

392. Gold in the head is oftenest due to sitting or standing in 
a draught, or to going suddenly into the cool air when we are 
overheated, without puttiug on some additional clothing. Very 
often we know that we have been imprudent in this way and 
can feel the cold coming on, and then a mustard foot-bath may 
prevent it. 

393. Use of the Sense of Smell. — With the sense of 
smell we are able to enjoy agreeable odors. But what is im- 



THE SENSES. 189 

portant is, that we are also able to smell bad odors, thus pro- 
tecting the body by informing us of the whereabouts of obnox- 
ious things which should be avoided, especially of impure air. 
It enables us to select the proper food, and to refuse that which 
is unfit to eat. It often protects our bodies and homes by 
enabling us to smell smoke and in this way to discover the 
existence of a fire. 

394. Sweet Scents. — To smell the sweet odors which 
flowers give off, is very agreeable. Odors are given off by the 
oils existing in the flowers of plants. These oils are extracted 
from the flowers, and this is then called perfume. Many per- 
sons use this perfume to put upon their handkerchiefs and 
clothes so that they may smell sweet ; but, as a rule, the most 
refined people do not use perfumes. If you always keep the 
body clean and brush your teeth often you will not need any 
perfume ; for if the body is clean, it always smells sweet. 
Soap and water are better than perfume to tidy people. 



SYNOPSIS. 

The Nose : 

1. Parts: 

(1.) Two bones forming bridge. 

(2.) Gristle. 

(3.) Two nostrils. 

(4.) Three shelves running from front to rear. 

(5.) Shelves covered by soft membrane. 

(6.) Membrane of upper two shelves supplied with 

(7.) Nerves of smell which descend in a bunch from brain. 

2. Functions : 

(1.) Lower passage for air. 

(2.) Upper part for sense of smell. 

a. Great acuteness in some of lower animals. 

b. Blunted in cold in head. 

c. Use — To protect us from impure air and im- 
proper food. 



190 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



QUESTIONS. 

1. What are the uses of the nose? 2. Which part of the nose 
serves for breathing ? 3. Which part is used for smelling ? 4. Of 
what is the nose formed? 5. Where is the bridge of the nose? 6. 
What are the nostrils? 7. What do we find in the inside of the 
nose ? 8. Where are the nerves of smell? 9. Where do they come 
from ? 10. How is the nose connected with the throat ? 11. Where 
do we find the more acute sense of smell, in man or in the lower 
animals ? 12. Give an example. 13. What is meant by a cold in 
the head ? 14. What is this often caused by ? 15. What are the 
uses of the sense of smell ? 16. What parts of plants usually give 
off the sweet scents ? 17. What can you say about the habit of 
using perfume upon the handkerchief or clothing ? 



THE TONGUE AND THE SENSE OF TASTE. 

The tongue is the organ with which we taste our food. 

395. Structure of the Tongue.— This organ consists 
almost entirely of muscle tissue. Its under surface is smooth, 
and its upper surface very rough. This roughness is due to a 
large number of small projections. These can be seen better 
in the lower animals than in man, and serve two purposes : 
First, they are the parts which give us taste; the nerves of 
taste ending in rounded extremities in these elevations. The 
other use is to feel the food in our mouth and to discover 
whether it is chewed sufficiently fine, and mixed enough with 
the saliva, before it is swallowed. The lower animals, as dogs 
and cats, are enabled to scrape off bones by means of these 
projections. 

396. Uses of the Tongue. — The uses of the tongue are : 
(1) as the organ of taste ; (2) to revolve the food in the mouth, 
to mix it tvith the saliva, to separate hard portions of food, as 



THE SENSES. 



191 



seed and shells, and to assist in swallowing ; and (3) as the 
principal organ in speaking. The importance of the sense of 
taste need not be pointed oat especially. It enables us to 
choose our food and to avoid what is unfit to eat ; it prevents 




Fig. 88. — The Human Tongue ; above, the Epiglottis is also seen. 



us from eating improper food ; it increases the appetite and 
makes us enjoy our meals when the food is to our liking. 

397. Abuse of the Sense of Taste.— The sense of taste 
adds much to our enjoyment. It is necessary, however, to 
prevent it from enjoying too many liberties, otherwise we 



192 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

shall be eating too much, become gluttons, and suffer in health. 
In selecting our meals, we are guided by what is wholesome, 
nourishing, and digestible. 

SYNOPSIS. 
The Tongue. 
Structure — 

1. Formed of muscle-tissue. 

2. Smooth on under surface. 

3. Kough on upper surface, due to 

4. Small projections which serve to 

a. Feel food to see if properly chewed. 

b. Taste with, since nerves of taste end here. 
Uses — 

1. Organ of taste. 

2. To revolve food in mouth, mix it with saliva, remove hard 

portions, and assist in swallowing. 

3. To assist in speaking. 

QUESTIONS. 

1. Describe the tongue. 2. Of what kind of tissue is it made 
up ? 3. Which surface is rough ? 4. What is this roughness dne 
to? 5. Of what use are these small elevations? 6. What are the 
uses of the tongue ? 7. What are the uses of the sense of taste ? 
8. How might we abuse the sense of taste ? 



THE EYE AND THE SENSE OP SIGHT. 

398. Protections to the Eye. — The eye is one of the 

most delicate organs in the body. It is placed in the large 
opening in the skull found just below the forehead, on each 
side of the nose, called the orbit. This affords it considera- 
ble protection. Besides this, it is also protected by the eye- 
brows, eyelids, and eyelashes. In the orbit the eye rests upon 
a soft cushion of fat. 



THE SENSES. 



193 



399. The Eyelids. — These serve to protect the eyes by 
their quick movement in closing, thus keeping out dust. They 
keep out the light when too strong, or during sleep. 

400. The Eyebrows and Eyelashes. — These keep the 
perspiration from rolling into the eyes, and keep out dust. 
They should never be cut, for this will not cause them to grow 
any longer and injures them by making them thick and stiff. 



End of choroid coat in front. . 

Space behind iris 

Membrane supporting the lens 

Cornea s 

Aqueous humor m^~ 

■ 

Lens BjP 

Iris I 

Space behind iris 

End of choroid coat in front . 



Fig. 89.— The Human Eye (Cut Across 




Its Different Parts and 



the Interior. 



401. Parts of the Eye. — The eye is spherical in shape, and 
measures about an inch in diameter. Its front portion is per- 
fectly transparent, and is called the cornea. But behind the 
cornea, which forms about one-fifth of the circumference of the 
eyeball, it is opaque and white, and can be separated into three 
layers, or coats. The outermost layer is hard and strong, and 
it preserves the form of the eyeball ; it is called the white of 
the eye, or the sclerotic coat. The middle layer is dark-colored, 
and is called the choroid coat. The inner layer is called the 



194 

retina, and is of great importance, because the nerve of the eye 
sends its branches to it, and it is the portion of the eye with 
which we see (Fig. 89). 

402. Looking into the eye, we see in the centre a black spot 
which is called the pupil. It is a round opening in a mem- 
brane which acts as a partition to this part of the eye. This 
membrane is a colored ring which surrounds the pupil and is 
really a curtain hanging behind the clear part of the eye. It is 
called the iris. 

403. Behind this curtain, the iris, is a round transparent 
body, about the size of a cherry-pit, which is called the lens. 
It is perfectly clear and its shape is like that of a small magni- 
fying glass ; but it is softer, like a hard jelly. It is supported 
behind the iris, just where the transparent part of the eye joins 
the opaque portion, by a delicate membrane, and is round, but 
flattened somewhat in front and behind. 

404. The interior of the eye is filled with fluid. Just be- 
hind the cornea, extending to the lens, is a space which is 
filled with a watery fluid called the aqueous humor. The 
rest of the eyeball (behind the lens) is filled with a clear 
substance like white jelly, called the glassy body or vitreous 
humor. 

405. The Iris. — It has just been explained that this is a 
curtain placed in front of the lens of the eye. There is a round 
opening in the centre, by which light is admitted to the eye ; 
this is the pupil. The pupil changes its size very often. When 
we look at anything in the distance the pupil becomes large ; 
when we look at objects close by it becomes very small. The 
pupil also regulates the amount of light which should enter the 
eye. In going into a bright light, as for instance into the sun, 
the pupil becomes very small ; if it did not do so the light 
would be too bright and would injure the eye. It is very 
dangerous to the eye to try to look at the sun. In the twilight, 
when the light is dim, you will notice that the pupil becomes 
very large. 



THE SENSES. 195 

406. The Muscles of the Eye. — It is wonderful bow 
rapidly the eyes move ; but this is necessary to protect the 
body. The rapid motion of the eyes is also necessary so that 
they can act together. If you were to press upon one eye so 
that it could not move, and then were to move the other, every- 
thing would look double ; so that the two eyes must move to- 
gether if we want to see singly and plainly. There are six 
small muscles (Fig. 90) attached to each eye, which make its 
movements so rapid. Sometimes, one of these muscles does 
not act so well as it should ; then the eye turns in all the time 




Fig. 90. — The Muscles Attached to the Eyeball and to the Upper Lid. 

or constantly looks outward ; the person is then cross-eyed, or 
squints. Some children are born this w T ay and it is not right to 
make fun of them. Sometimes children turn their eyes so as 
to imitate cross-eyed persons — a very injurious habit. 

407. How We See. — It may seem strange to say that we 
really see with the brain, but such is the case. Of course the 
eyes are necessary, and without them we should be blind ; but 
the brain is also necessary for sight. If a certain part of the 
brain be injured we cannot see, even though our eyes remain 
as clear and bright as they were before. 

408. Resemblance of the Eye to a Photographer's 
Camera. — The eye resembles the box which the photographer 
uses to take pictures, and which is called a camera. Let us see 
how it resembles the photographer's camera. In the first place 



196 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the photographer cannot take a picture in the dark, nor can we 
see in the dark. Secondly, in the front of the camera there is 
a lens of glass ; we also have a lens, though it is of course not 
of glass, but of a better and softer material. Again, in the 
back of the photographer's camera is a glass plate, upon which 
the picture falls and is taken ; in the same way in our eyes the 
retina serves as a plate upon which to take the picture. Anything 
which we see forms an image upon the retina. This image 
lasts only a short time, but long enough for us to see it. Fi- 
nally, you have probably noticed how the photographer puts a 
black cloth over his head and the back of the camera so as to 
keep it dark ; the middle, colored coat -of the eye — the choroid 
— serves to darken the inside of the eye. 

409. The Nerve of the Eye. — Connected with the back 
of the eye is a portion resembling a cord, which passes to the 
brain. This is the optic nerve, or nerve of the eye. It is the 
nerve which connects the eye with the portion of the brain 
used in seeing. On arriving at the eye the nerve spreads out 
in the interior of this organ and forms the innermost layer, 
which is called the retina. By looking into the interior of the 
eye with an instrument, the oculist can see this layer. It is 
shown in Fig. 91, the central spot being where the nerve enters 
the eye ; at this point blood-vessels also enter the eye and then 
divide and spread out in a very pretty manner. 

410. Blindness. — If the optic nerves of both sides become 
diseased, or both retinae become changed, the person may be- 
come totally blind, even though the eye appears perfectly 
healthy on the outside. These nerves carry the sight from the 
eye to the brain, with which seeing is really done. 

411. Images. — The word image has been used and will re- 
quire some explanation. If you look into a mirror you will see 
your face — this is an image of your face. The light strikes 
your face and from it passes to the mirror ; there it forms an 
image ; from this image the light passes into the eye and forms 
another image upon the retina, which we see. 



THE SENSES. 



197 



412. The Tears. — The eye is constantly kept moist by 
being bathed with tears. At the outer part of each eye be- 




Pig. 91. — A View of the Interior of the Eye, as Seen with the Oculist's Instrument. 




Fig. 92.— The Lachrymal Gland, Sac, and Duct. 



tween it and the bone forming the roof of the orbit, is a small 
body called the lachrymal gland (Fig. 92), meaning tear-gland. 
This body is constantly pouring the tears over the eye so as to 



198 

keep it moist. Even during sleep this takes place, though 
there is then much less produced. When we are awake the eye 
is moving constantly and this movement spreads the tears over 
the eyeballs. After the tears have moistened the eye, they are 
collected again and escape into the nose. If you look at your 
lids you will notice near the inner corner of the eye, a small 
spot about the size of a pin's point. There is one of these on 
the lower lid and one on the upper. The tears pass into these 
openings and then into a small bag near the nose, called the 
tear-sac ; then they are carried down into the nose by a tube 
called the tear-duct, or nasal duct (Fig. 92). You have noticed 
how the nose runs after crying. This is because there is so 
much more of this fluid discharged into the tear-duct. If any- 
thing gets into the eye, the lachrymal gland produces more of 
the tears and they flood this organ until the intruding body is 
swept away. If we become very sad or very angry, tears be- 
come very abundant. 

413. Care of the Eyes. — There is no organ in the body 
which contributes so much to our comfort, our enjoyment, and 
our knowledge, as does the eye. And yet the eye is constantly 
being misused. If you have good eyesight you should take 
care of your eyes so that it does not get bad, and if your eye- 
sight has already become bad you should see that it does not 
get worse. Some of the most common rules for the care of the 
eyesight are the following : 

414. After having read a long time, it is well to stop and rest 
the eyes ; for the eyes, like any other part of the body, cannot 
be used continuously. It is quite natural that the eyes should 
feel tired and begin to pain after we have used them a long 
time ; this is nature's sign that they need rest. 

415. Never read in a poor light. You may be finishing a 
chapter in your book and you notice that it is beginning to get 
dark, yet you do not stop until you get to the end of the chap- 
ter even though you strain your eyes. This is wrong and the 
eyes suffer for it. 



THE SENSES. 199 

416. Never read very fine print if you can help it. 

417. In reading, have the light come over your shoulder and 
thus fall upon the book or paper without going directly into 
your eyes. It is better to sit with your back to the window 
and thus have the light come over your shoulder, and preferably 
over the left shoulder. This precaution is especially useful at 
night, for the glare of the gaslight or lamp is very tiring to the 
eyes ; while if the light is behind you and falls over your shoul- 
der there is just as much light upon your book or paper and yet 
the eyes are spared the brightness. 

418. Never read ivhile lying upon the back. You cannot read 
comfortably in this position and you have to strain the eyes 
so that it is very tiring. If for any reason you must read lying 
down, do so with the shoulders and head raised into a half- 
sitting position. 

419. There may be some excuse for business men's reading in 
the cars, for often this may be the only time they have to read 
the daily papers. But there is no reason why children should 
do this. It is injurious, in the first place, because the light is 
usually poor, but chiefly, because the constant jolting of the 
car makes the page unsteady and requires a constant strain 
upon the eyes to keep the place. 

420. Never wash your eyes with water ivhich another person has 
used on his face. Never use a towel for wiping your face, which 
another person has had to his face, unless this person is one of 
your family and you know he has no eye disease. There is a 
disease of the eyelids, called granular lids, which is very con- 
tagious ; many children contract it in school by using the 
towel which another child who had the disease has used. 

421. Do not stoop when you read, but raise the book so that you 
can hold the head erect. 

422. Weak Sight. — Some persons are born with weak eyes 
— that is, they do not see so well as other people and have to 
wear glasses. Some of these people are called near-sighted, 
others are called far-sigh ted. If the doctor advises you to wear 



200 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

glasses you should not be ashamed to do so. Only vain per- 
sons object to wearing glasses when they are necessary. 

423. Old Sight. — After persons are about forty years old 
they can still see distant objects well ; but they need glasses in 
looking at near objects. 



SYNOPSIS. 
The Eye : 

1. Protections . 

a. Surrounded by bony orbit. 

b. Rests on cushion of fat. 

c. Eyebrows — Keep off perspiration. 

y e i s - ( Keep out dirt, light, and perspiration. 



e. Eyelashes. 
2. Parts : 

a. Coats : 

1. Opaque part behind. 

a. Sclerotic — Outer, white, dense. 

b. Choroid — Middle, colored, brown. 

c. Retina — Inner, composed of nerve-tissue. 

2. Transparent part in front — Cornea. 

b. Iris — Curtain to keep out light ; in centre is 

c. Pupil — Size changes. 
cl. Lens. 

e. Fluids : 

1. Aqueous humor. 

2. Vitreous humor. 

f. Muscles — Six small ones attached to eye, to move it 
in all directions. 

g. Nerve —Attached behind and passing to brain, with 
which we really see. 

h. Lachrymal gland — Near the eye, gives off the tears, 
which keep the eyeball moist, collected by tear-sac and es- 
cape by tear-duct into nose. 
Care of the Eye : 

1. Requires rest when used for long time. 

2. Good light in reading. 

3. Injurious to read very fine print. 



THE SENSES. 201 

4. Light should come from behind — over shoulder. 

5. Not well to read while lying down. 

6. Not well to read while riding in cars. 

7. Bisk of contracting eye disease in using towels or water 
that other people have used, to eyes. 

8. In reading, sit erect. 

9. Weak sight requires glasses. 

10. Old sight (after forty) requires glasses. 

QUESTIONS. 

1. In what are the eyes placed? 2. How are the eyes protected ? 
3. What do the eyelids do ? 4. Of what use are the eyebrows and 
eyelashes? 5. Why should we not cut the eyelashes or the eye- 
brows ? 6. What is the shape of the eye ? 7. What is the cornea ? 
8. How many layers has the back part of the eye ? 9. What is the 
back part called ? 10. Which is the most important of these three 
layers ? 11. What is the pupil ? 12. What is the iris ? 13. What 
is the lens ? 14. With what is the interior of the eye filled ? 15. 
What two fluids do we have in the eye ? 16. Is the pupil always of 
the same size? 17. When does it become large? 18. When does 
it become small ? 19. Of what use is the pupil ? 20. How many 
muscles are there to each eye ? 21. Of what use are these muscles ? 
22. What is the cause of cross-eyes ? 23. With what part of the 
body do we really see, the eye or the brain? 24. How is this 
proven ? 25. What instrument may our eye be compared with ? 
26. Explain in what ways our eye resembles the photographer's 
box ? 27. Where is the nerve of the eye ? 28. What does it do ? 
29. What do we mean by an image ? 30. How is the eye kept 
moist ? 31. Where is the body which produces the tears ? 32. 
What is it called ? 33. How are the tears collected again ? 34. 
What becomes of them ? 35. Where is the tear-sac ? 36. Where is 
the tear-duct ? 37. W T hat causes the tears to flow more than usual ? 
38. Why should We stop after we have read a long time ? 39. What 
does a tired feeling or pain in the eye after reading mean ? 40. 
What sort of light should be avoided ? 41. Where should the light 
come from when you read ? 42. Should it come from the front ? 
43. Why not? 44. Can a person read lying down, without injury 
to his eyes ? 45. Why not ? 46. Why should we not read on the 



202 



ANATOMY, PHYSIOLOGY, AND HYGIENE 



cars. 47. Why should we not use towels that other persons have 
used to their faces ? 48. What disease of the eyelids may be con- 
tracted in this way ? 49. What position should you take when you 
read? 50. What is meant by weak sight? 51. After what age do 
people need glasses for reading ? 



THE EAR— THE SENSE OF HEARING. 



424. Like the eye, the ear is an organ which adds very much 
to our comfort, pleasure, and knowledge. 

425. Parts of the Ear. — The ear is divided into three parts : 
An outer, a middle, ahd an inner. 

426. The Outer Ear is the part seen at the side of the 
head. It is expanded and formed 
of gristle, covered with skin. Its 
shape is not only ornamental, but 
useful, for it serves to collect the 
sound and lead it into the deeper 
parts of the ear. As a rule, we 
cannot move the ears ; but in the 
lower animals the ear can be moved 
in all directions, and in this way 
these animals tell where the sound 
comes from. From this outer part 
of the ear there is a canal about an 
inch long which leads to the next 
part, or the middle ear. In this 
canal is usually found a little yel- 
lowish substance, which we call 

ear-wax, which serves to keep the 
canal soft and moist and to keep out insects, which dislike this 
wax. 

427. The Middle Ear. — The middle part of the ear contains 
the drum, and is only about half an inch across. It is at the 




Fig. 93.— The Outer 



THE SENSES. 



203 



bottom of the canal which leads from the outer ear. Between 
the two a sheet of membrane is stretched which is called the 
drum-membrane. In the middle ear itself there is nothing but 
three small bones which are joined so as to form a small chain. 
One end of this chain is fastened to the drum-membrane and 
the other to the inner ear, so that these bones connect the 
outer ear with the inner ear. 




Fig. 94.— The Different Parts of the Organ of Hearing. 1, The outer ear; 2, the canal 
leading from the outer to the middle ear ; 3, middle ear ; 4. Eustachian tube ; 5, nerve of 
hearing ; G, the internal ear. 



428. Bones of the Ear. — These bones are shown in Fig. 
95, and are very interesting. They are named, according to 
their shape, the hammer, the anvil, and the stirrup. 

429. Connection Between the Ear and the Throat. 
— Perhaps you may have noticed that sometimes when you 
blow your nose hard there is a stuffed feeling in the ears ; or 
that when your throat was sore your ears were also affected. 
Sometimes, too, when you swallow you feel something in your 



204 

ear. This is because there is a tube which runs from the throat 
to the middle ear. It is very important that this tube remain 
open, for otherwise air cannot enter the middle ear as it should 
and we do not hear well. This tube is called the Eustachian 
tube, after the physician who first described it (Fig. 94, 4). 

430. The Internal Ear. — This part of the ear is placed 
very deeply in the bone. There are several circular canals and 
a winding passage like a staircase hollowed out of the bone, 
and in these the inner ear is contained (Fig. 96). In these 
circular canals we find a delicate membrane and a fluid on 





Fig. 95.— The Small Bones of the Ear. A, FlG. 96.— The Internal Ear. 

The hammer ; B, the anvil ; C, the stirrup. 



each side of it. The arrangements in the internal ear are very 
intricate. 

431. The Nerve of Hearing. — The nerve of hearing is at- 
tached to the internal ear and from this part it passes to the 
brain (Fig. 94, 5) ; it therefore conducts the sound to the brain 
just as the optic nerve conducts sight to the brain. 

432. Sound. — Before studying how we hear, it is necessary 
to understand how sound is produced. Sound is produced 
whenever the air is made to vibrate — that is, whenever the air 
is put into motion resembling waves. You will understand 
this better if you think for a moment of the water : Suppose 
when a pond is quiet, you throw in a stone ; this causes a mo- 



THE SENSES. 205 

tion in the water and you will then see rings start out from the 
point where the stone fell, these rings becoming larger and 
larger until they are finally lost ; but all the time these rings 
or very small waves have been going farther and farther from 
the centre. Now imagine the same thing occurring in the air. 
If you strike a bell, for instance, you know that the bell is 
vibrating, because if you put your finger on it you can feel 
this motion. This motion is given to the air, and the air 
vibrates in the same way, except that the vibrations travel 
through the air to our ear. 

433. Solids conduct sound even better than air does ; if you 
place your ear at one end of the table and strike the other end 
the sound which you hear will be very loud. 

434. How We Hear. — Now that we know what sound is, 
let us study how we hear. The waves of sound pass through 
the air and reach the outer ear, which is shaped so as to collect 
them and lead them into the canal to the drum-membrane. 
The waves of sound beat against this membrane and cause it 
to vibrate ; when this membrane vibrates, the bones of the 
middle ear must also move to and fro, because they are at- 
tached to it. The bones of the middle ear carry the vibra- 
tions to the internal ear, where the nerve of hearing ends in 
a large number of fine hairs, and these carry the sound to the 
brain. 

435. Deaf- Mutes. — Persons who cannot hear when they 
are children, and therefore cannot imitate sounds from other 
people, are called deaf-mutes. These unfortunate people have 
voices just like others ; but they cannot hear the sounds, and 
therefore they cannot speak in the ordinary way. But they 
can make themselves understood in two ways : One way is by 
means of signs and letters which they make with their fingers, 
and which they learn to do very rapidly. The second method, 
and the most recent, is to teach the deaf-mutes to talk by hav- 
ing them imitate the motion of our lips. It is surprising how 
well they learn to do this ; some of them being able to carry 



206 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

on a conversation and yet not hear what is spoken, but under- 
standing it by watching the movement of the lips. 

436. Care of the Ears. — We should never try to pick out 
the wax in the ears with hairpins and other sharp instruments. 
A little wax is quite natural, and if too much is there it is best 
to let the doctor remove it, for we may injure the delicate 
parts of the ear. 

437. If water gets into the ear during bathing, hold the head 
over to one side and pull the outer ear up and down gently, 
and it will flow out. 

438. If an insect should crawl into the ear, a little soap and 
water will kill it, and at the same time bring it out. 

439. A blow upon the side of the head or over the ear is 
dangerous, because it sometimes affects the brain ; it may also 
tear the delicate drum-membrane and thus interfere with good 
hearing. 

440. The ears do not need to be washed out when they are 
healthy ; simply wash the outer ear and do not meddle with 
any of the deeper parts. 

SYNOPSIS. 

The Ear : 
Parts : 

1. Outer ear — Collects sound. 

2. Canal leading from outer to middle ear. 

3. Middle ear : 

a. Drum-membrane. 

b. Bones : (1) Hammer, (2) anvil, (3) stirrup. 

4. Internal ear — Nerve of hearing ends here in fine hairs, 
and conveys sound to brain. 

5. Eustachian tube — Leading from throat to middle ear. 
How we Hear : 

1. Vibration of sounding body. 

2. Vibration of air. 

3. Collection of sound by outer ear. 

4. Conveyance of sound by canal. 

5. Strikes against drum-metnbrane. 



THE SENSES. 207 

6. Vibrations conducted by chain of bones to 

7. Internal ear, where they strike the hair-like ends of 

8. The nerve of hearing, which conducts sound to 

9. Brain. 



QUESTIONS. 

1. Into what three parts can the ear be divided? 2. Why is the 
external ear shaped as it is ? 3. Can the lower animals move their 
ears ? 4. Of what use is this to them ? 5. *What leads from the 
outer ear down to the middle ear ? 6. What is ear-wax ? 7. What 
are its uses ? 8. What is another name for the middle ear ? 9. 
Where is the drum-membrane ? 10. What is in the middle ear ? 
11. How are the bones of the middle ear arranged ? 12. What are 
the names given to the bones of the middle ear ? 13. What con- 
nects the throat with the middle ear ? 14. Where is the internal 
ear ? 15. What is its form ? 16. What is in the internal ear ? 17. 
Where is the nerve of hearing ? 18. What does it do ? 19. How is 
sound produced ? 20. What conducts the sound ? 21. Can solids 
conduct sound ? 22. How can you prove this ? 23. Explain how 
we hear ? 21. What is meant by a deaf-mute ? 25. Has a deaf- 
mute any voice ? 26. Why cannot he talk without special teaching ? 
27. How do deaf-mutes make themselves understood? 28. Why 
should we not try to pick out the wax in our ears ? 29. How would 
you get rid of any insect that crawled into the ear ? 30. Why is a 
blow upon the side of the head or over the ear dangerous ? 



CHAPTER XII. 
STIMULANTS AND NAECOTICS. 

441. Stimulants excite the system or some part of it. Among 
the most common stimulants are tea, coffee, and liquids contain- 
ing alcohol. Many drugs act as stimulants ; ammonia and 
camphor are good examples of medicines prescribed for this 
purpose. 

ALCOHOL AND ALCOHOLIC DRINKS. 

442. Alcoholic drinks are so called because they contain 
alcohol. It is this ingredient which makes them intoxicating. 
Non-alcoholic drinks, such as ginger ale, sarsaparilla, soda water, 
and lemonade, are free from alcohol, and are harmless. Let us 
now study what alcohol is, how it is made, its uses and abuses, 
and the danger and great injury to man which it causes. 

443. Properties of Alcohol. — Alcohol is a clear, colorless 
liquid, resembling water in appearance, but lighter ; it has a 
pleasant smell ; it takes fire easily and burns with a faint bluish 
flame, giving off no smoke, and hence is very useful for some 
heating purposes. Alcohol is sometimes called spirit. Its 
taste is very hot and burning. If we leave a little in a saucer, 
we soon find that it has disappeared into the air, and we say it 
has evaporated. 

444. Uses of Alcohol. — Alcohol is very useful to us in 
many ways. It dissolves a great many things which water will 
not dissolve. Oils and resins will not mix with water ; but al- 
cohol dissolves them. The druggist uses it pure or mixed with 



STIMULANTS AND NATCCOTICS. 209 

water to extract the active principles of roots, herbs, barks, and 
leaves. In this way many medicines are made and called tinct- 
ures. It will not freeze, no matter how low the temperature ; 
hence it is used to fill the tubes of thermometers which are to 
be used in very cold countries, or to register low temperatures. 
It has the property of preserving many animal and vegetable 
tissues and keeping them from becoming offensive. 

445. Fermentation. — If you take anything which contains 
starch, whether it be corn, rye, potatoes, or anything else, add 
yeast and water to it, and mix them, you will soon find that the 
starch in these substances has turned into sugar. If you 
allow the mixture to stand longer and if you warm it slightly, 
little bubbles of gas will be seen escaping into the air ; we say 
it is fermenting. If any one has seen sweet cider becoming hard 
and then sour, he will have noticed the bubbles of gas rising ; 
this is an example of fermentation. At the same time that this 
gas is given off, we find the liquid is becoming less sweet than 
it was. After a time it will have lost all its sweetness and have 
the taste of alcohol. So that, first the starch has been changed 
into sugar, and then the sugar has become changed into alcohol. 
The alcohol remains in the liquid, while the gas, which is poi- 
sonous, escapes into the air. Two poisons have taken the place 
of the starch or sugar which existed before. The gas, known 
as carbonic acid gas, is the same poisonous substance which is 
given off in the expired breath and which collects in damp 
cellars and old wells. This process which changes sugar and 
starch into alcohol is but one form of fermentation, and is 
brought about by the growth of minute living bodies which are 
always present in the air and hence soon fall into any liquid 
which is exposed. 

446. Different Kinds of Fermentation.— If a watery 
liquid containing vegetable substances be exposed to the air in 
a warm place, it soon spoils. Minute living particles, which 
are constantly present in the air, have fallen into this liquid, 
have grown, and in doing so have produced the changes which 



210 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

we call spoiling. The two most important kinds of fermenta- 
tion are acetous, or vinegar, and vinous, or alcoholic. 

447. Acetous Fermentation. — The change of any liquid 
containing alcohol into vinegar is an example of this form of 
fermentation. If we desire to obtain vinegar, we need only ex- 
pose cider or wine to the air in a warm place ; then the change 
will take place and the liquid becomes sour. 

448. Alcoholic Fermentation. — The yeast plant is the 
particular kind of living germ which changes starch into sugar 
and then into alcohol. Such germs are constantly present in 
the air ; but we cannot rely upon them for definite results, and 
hence it is more satisfactory to add yeast to the fluid which we 
wish to subject to alcoholic fermentation. 

Sometimes a sugary liquid is taken at once, such as the juice 
of grapes from which wine is made ; in which case it is not 
necessary to change starch into sugar, for sugar is already 
present. 

449. If the preparation is to be an alcoholic drink, it requires 
clearing and flavoring. If the drink is to be wine, beer, ale, 
porter, or cider, this is done by allowing the liquid to stand, 
and pouring off the clear part, and straining it. If it is to be 
one of the liquors, whiskey, brandy, rum, and the like, the 
liquid is placed in a large vessel and heated. The heat drives 
off the alcohol and some of the water and some flavoring mat- 
ters ; these are collected and make liquor. This process by 
which a fluid is turned into a vapor by heat and collected again 
in the form of a liquid is called distillation. Cold hastens the 
return of the vapor to a liquid form. If you breathe upon a 
pane of glass in winter, moisture will collect. This is the 
moisture contained in the expired air which is condensed by 
the coldness of the window-pane. 

If pure alcohol is wanted, it must be driven off by heat sev- 
eral times in succession, being collected again each time. 

450. Varieties of Alcoholic Drinks. — All alcoholic drinks 
are intoxicating in proportion to the amount of alcohol which 



STIMULANTS AND NARCOTICS. 211 

they contain. They can be divided accordingly into four 
classes : 

451. (1.) Beers, including porter and stout, ales and cider, 
usually contain from two to six per cent, of alcohol. 

Beer is made from barley. This is moistened and kept in a 
warm place until it sprouts, the object of which is to change the 
starch into sugar. As soon as it commences to sprout, it is 
placed in an oven and heated so as to stop the growth of root 
and stem, which we call sprouting ; this forms malt. The malt 
is crushed, mixed with hot water and the mass allowed to stand ; 
the sugar, salts, and nutritious portions of the malt are thus 
dissolved and form wort. This is strained, and, after hops are 
added to give a slightly bitter taste, boiled. It is then drawn 
off, cooled to the ordinary temperature of the room, mixed with 
yeast and allowed to ferment. After fermentation has proceeded 
to a certain point the yeast is separated and the clear fluid is 
drawn into casks, forming beer. 

452. Ale, porter, and stout are made in a somewhat similar 
manner ; the dark-brown color of porter is produced by adding a 
quantity of charred malt. Cider is the fermented juice of apples. 

453. (2.) Wines usually contain from eight to seventeen per 
cent, of alcohol. They are made from the juice of grapes, which 
is simply expressed and set aside in large vats. If there be much 
sugar present, the wine remains siveet ; if the proportion of 
sugar be small, the wine is called dry. Effervescent wines, 
such as champagnes, are bottled before fermentation is com- 
pleted. Home-made wines, such as elderberry wine, are just 
as intoxicating as other kinds. 

454. (3.) Liquors contain about one-half alcohol. The only 
difference in the various kinds is the flavor, which depends upon 
the kind of grain used to furnish the alcohol, or upon whatever 
flavoring is added afterward. Whiskey is made from rye or 
corn, brandy from grapes and other fruit, rum from molasses ; 
gin is flavored with juniper, and absinthe with wormwood. 
Many liquors are made artificially by mixing equal parts of al- 



212 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

cohol and water, and adding some flavoring material and 
enough coloring substance to give the compound the proper 
color. 

455. (4) Cordials are clear liquids, variously colored, contain- 
ing a large amount of alcohol, and flavored with various aro- 
matic oils, such as peppermint, anise, fennel, orange, etc. They 
are made artificially. 

456. Many of the much-advertised bittern and tonics contain 
large amounts of alcohol. They are therefore capable of doing 
great injury, since they are deceptive and often establish the 
craving for alcoholic drink in persons who were unaware of the 
fact that they were taking what practically amounted to liquor. 

457. General Effects of Alcohol and Alcoholic 
Drinks. — Having studied what alcohol is and how alcoholic 
drinks are produced, the effects will now be considered. 

Alcohol in various forms is often prescribed by the physi- 
cian for use as a medicine ; doctors, however, realize how 
much responsibility attaches to their recommendation of 
liquids containing alcohol even for this purpose ; for the alco- 
hol habit is begun in many by the well meant directions of the 
medical adviser. In certain fevers and wasting diseases, alco- 
holic drinks are prescribed not only as stimulants but as food. 
But because it may act as a food under such conditions, we 
are not justified in assuming that it can be used as a food at 
all times ; ordinarily it does not act as a food. It is intoxicating, 
and the very meaning of the word, which is derived from a 
Latin word signifying arrow-poison, indicates its nature. It 
may be argued that many people are in the habit of using 
moderate amounts of alcoholic drinks without any apparent 
harm ; but the same can be said of every other injurious sub- 
stance. No one will deny that the world would be infinitely 
better off if there was no such thing as alcoholic drink, or even 
alcohol itself. Some other substance would be found to take 
its place. If a prison be visited, and the convicts be asked 
about the crimes which brought them there, it is astonishing 



STIMULANTS AND NARCOTICS. 213 

how many of them will blame drink. Many a man, who would 
otherwise have been good and useful, has been made a crim- 
inal by this poison. It may safely be said that there is no 
cause of crime so great and widespread as drink. 

458. There is an erroneous idea which is quite prevalent 
that alcohol increases the warmth of the body, muscular 
power, and the activity of the brain ; but it is a fact which has 
been proven over and over again that it has just the oppo- 
site effect. 

459. There may be a feeling of warmth to the body, after alco- 
holic drink has been taken, but this is only on the surface and 
soon passes away, and then the warmth of the body is lessened. 
This was shown very well in several North-polar expeditions, 
where men who drank freely of liquor were frozen before the 
rest. Persons who are exposed to great cold know from ex- 
perience that they do better without alcoholic drink. 

460. Where great muscular feats are attempted, abstinence 
from alcoholic drinks is usually part of the system of training. 
Even prize-fighters, limited as their intelligence usually is, 
have found this out from experience. Crews in training for 
boat-races commence their period of preparation by abstaining 
from indulgence in alcoholics. Experiments upon whole armies 
of men have demonstrated the fact that soldiers can withstand 
fatigue and exposure much better when deprived of alcoholic 
drinks. 

461. Upon the brain alcohol acts by first exciting it ; but this 
is soon followed by the opposite effect, and the person becomes 
dull and stupid. People who do much brain work know that 
they are more active when they let wine, beer, cordial, and 
liquor alone. Alcohol excites the brain in one way, but it 
excites it so that the person becomes noisy, and often wishes to 
fight ; hence it does not excite the most desirable function of 
the brain, namely, the intellect. 

462. Effects of Alcohol upon the Tissues of the 
Body. — Alcohol, in the form of drink, has the following effect 



214 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

upon the tissues : It irritates the stomach and constantly makes 
it red ; after a while the wall of the stomach becomes tough, 
and is no longer suited for its work. When a large quantity 
of alcoholic drink is added to the food, it prevents it from being 
digested. It often causes nausea and vomiting, and the vom- 
ited material will have the same form as when swallowed, 
showing that alcohol interferes with digestion. Topers suffer 
constantly from dyspepsia. Alcohol has the same irritating 
effect upon the intestines. The liver, irritated by the alcohol 
in the blood, is apt to become enlarged and choked up with 
blood ; and finally it shrinks and becomes much smaller and 
denser than it should be. 

463. It causes the heart to act top rapidly, and this organ suf- 
fers changes which interfere with its action. After a while it 
may act imperfectly or irregularly. Muscle-tissue becomes 
changed to fat, and the heart being formed of such tissue suf- 
fers a like change. The blood-vessels lose their elasticity, be- 
come dilated and stiff. Upon the nose can be noticed how the 
veins of a drunkard become enlarged and prominent. 

464. The nerves soon become affected and the victim of 
alcohol is made unsteady, as is shown by the trembling hands 
and unsteady walk of the drunkard. The membranes covering 
the brain become thickened and tough. The eyesight suffers and 
even blindness may ensue as a result of wasting of the optic 
nerve. 

465. The power to resist disease is very much weakened in a 
person addicted to alcoholic drink ; and if such a person be- 
come ill with some serious disease his chances of recovery are 
very much fewer than if he had abstained ; this is particularly 
the case in pneumonia. If he meets with an accident it will 
take him longer to recover ; in the case of a fracture, the ends 
of the broken bone unite with much greater difficulty than in 
ordinary cases. 

466. Delirium Tremens. — Drinking often causes a condition 
of the nervous system which may result in death within a few 



STIMULANTS AND NARCOTICS. 215 

days ; this condition is known as delirium tremens. The affected 
person is out of his mind and there is great trembling of dif- 
ferent parts of the body, especially the tongue and the limbs. 
While in this condition, the drunkard is not responsible for what 
he does ; he attempts to do all sorts of violent things, such as 
fighting, attempting suicide and jumping out of the window ; he 
imagines he is pursued by enemies and that he sees rats, mice, 
snakes, and other animals ; his constant desire is to escape, and 
it is impossible to keep him quiet. Under these circumstances, 
the kindest parent is known to beat and injure his wife and 
children. The heart is often weakened so much, as a result of 
poisoning from alcohol, that death ensues from heart failure. 

467. Moral Effects of Alcoholic Drink.— Finally, the 
moral view of the effects of alcoholic drink must be considered. 
One has only to think how shocking it is to see an intoxicated 
man stagger along the street, holding on to anything for sup- 
port, with bad breath and dirty appearance. We should also 
consider the large amount of money which is uselessly spent in 
liquor saloons ; how many useful things it could buy, and how 
much good could be done with it. The time wasted in these 
rum shops, which would otherwise be spent at home with the 
family, should also be considered. 

Men do not become drunkards at once, but gradually. They 
commence with small quantities of drink, and the habit of drink- 
ing is formed and grows until they need larger and larger 
amounts to satisfy them. It is a habit which is very difficult to 
break off ; and once formed, men become slaves to it. The very 
effect of alcohol is to create a thirst which only an additional 
quantity of alcoholic drink will satisfy. 

NARCOTICS. 

468. Narcotics are drugs which benumb the system, relieve 
pain, and produce sleep. As a result of an over-dose, insensi- 
bility and death may result. Hence such drugs are powerful, 



216 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

and are dangerous when taken improperly. Narcotics benumb 
the brain, and thus produce an artificial sleep which usually 
lacks the refreshing qualities of natural sleep, the person who 
has taken them often waking up stupid and with a headache. 
This is especially apt to be the case when they are taken care- 
lessly and improperly, without the physician's advice. The 
narcotics used most frequently to produce sleep are opium, 
morphine, and chloral. Tobacco is a narcotic, but is not used to 
produce sleep. Alcohol also acts as a narcotic. 

469. Opium and Morphine. — Opium is a narcotic, but 
is probably the most useful medicine there is when ordered 
by the doctor in proper cases. It is a brown, sticky sub- 
stance, or it may come in the form of a brown powder. It is 
very poisonous. Most of it comes from India and the warm 
countries of that region. It is the juice of the unripe fruit of 
the poppy-plant ; this juice is allowed to dry, and then makes 
this sticky substance. From this is extracted white crystals, 
which have the same effect on the body as opium itself ; these 
crystals are called morphine. Opium dissolved in alcohol and 
water is called laudanum. 

470. The Opium or Morphine Habit. — Every one has 
probably heard of the opium habit, or, what is the same thing, 
the morphine habit. It is a habit people get into of taking these 
drugs whether they need them or not. Morphine and opium 
take away pain, and make persons sleep when they are sick and 
restless ; in such cases they do a great deal of good. 

471. But persons who have the morphine or opium habit do 
not take the drug for this purpose, but because they think it 
makes them feel good for the time being, and makes them forget 
any cares they may have. But after the effects pass off, they feel 
miserable. The stomach is upset, they are tired and nervous, 
have a very bad headache, and often feel like vomiting. They 
feel so bad that they take more and more, until finally they 
keep under the effects of it all the time. Some of them take 
the narcotic by the mouth, others smoke it in long pipes. 



STIMULANTS AND NARCOTICS. 217 

There is still another way in which these wretched people take 
morphine, and that is by piercing the skin with a hollow needle. 
Some of the morphine, dissolved in water, is forced under the 
skin from a small glass tube which is attached to the hollow 
needle. This is probably the most dangerous way of taking 
the drug, when used merely as a habit. 

472. Many persons who have this horrible habit have com- 
menced very innocently. Their doctor may have ordered the 
drug for them at a time when they needed it. But instead of 
stopping its use when they were well, perhaps they have con- 
tinued it, imagining it made them feel better, until it was too 
late, and they were prisoners of the habit. It is a habit which 
is very difficult to break off; it is said to be even more difficult 
to stop than either drinking or smoking. 

473. The effects of the opium and morphine habit upon the 
health show themselves very soon. The poor wretch soon be- 
comes nervous ; he cannot sleep at night ; he has no appetite ; 
if he takes any food he cannot digest and often vomits it ; he 
becomes thin and has a yellow complexion ; his mind changes 
and he loses his memory ; he has no longer the power to do 
right, and he is known to tell lies without hesitation in order to 
get some of the drug ; he becomes worse and worse, until, 
finally, when he has no more money to buy the drug, and his 
health is all broken up, he dies in the hospital or lunatic asy- 
lum, or often commits suicide. This is a horrible picture that 
has been drawn, but a true one. 

474. Chloral comes in white crystals which dissolve in 
water. People sometimes get into the habit of taking it 
regularly to make them sleep, and soon they cannot do with- 
out it ; and they have then what is called the chloral habit. 
They become nervous, pale, and weak, and have indigestion. 
The drug may have been prescribed originally by the physician, 
who intended it should be taken only temporarily. While not 
so bad a habit as the opium or morphine habit, it is neverthe- 
less a dangerous one, since the person constantly requires larger 



218 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

and larger doses to produce sleep, and thus soon begins to take 
poisonous doses. 

475. Cocaine. — Lately, a very important medicine lias 
been used, painted on a part, to take away pain ; it is called 
cocaine. The most important use of cocaine is in connec- 
tion with the eye. Oculists use it, dropping a few drops upon 
the eyeball, and thus rendering this organ insensitive to pain ; 
so that cinders and other foreign bodies can be removed and 
the eye operated upon without giving the patient the slight- 
est sensation. It is also taken internally, and some persons 
have gotten into the dangerous habit of taking it regularly. It 
excites them and makes them feel rested and it removes tired 
feelings for a time. But this is only temporary, and soon the 
person feels worse than before. If he gets into the habit of 
taking the drug regularly, it makes him nervous, and he gets a 
great many of the symptoms which were spoken of as occurring 
in the opium habit. This habit often affects the mind, and the 
unfortunate person becomes insane as a result of the cocaine 
habit. 

476. Tobacco. — Tobacco was first introduced into France 
in 1560, and in 1586 Sir Walter Raleigh introduced it into 
England. Previous to this time it had been used hy the Ameri- 
can Indians, and was smoked by them when Columbus landed. 
Tobacco is the leaf of a plant which grows and is cultivated in 
various parts of the United States and other countries. It is 
used very largely in smoking and chewing ; less in snuffing. 
Its injurious effects are due to a poisonous principle called nico- 
tine. 

477. Effects of Tobacco upon the System. — When 
used in small quantity, tobacco has a quieting effect upon the 
body and the mind, in some persons causing a sense of repose. 
In many persons this effect is not produced. Others again are 
made very uncomfortable by even the very smallest quantities. 

478. Like alcohol, tobacco soon causes a craving which results 
in the necessity for taking larger and larger quantities in order 



STIMULANTS AND NAKCOTICS. 219 

to satisfy. The tobacco habit causes a condition of the throat 
known as smokers sore throat. It often causes nausea, and a 
condition resembling sea-sickness attacks the smoker who is 
not accustomed to tobacco. The appetite often suffers and di- 
gestion is interfered with. Patpitation of the heart very fre- 
quently occurs. Nervousness and trembling are also very com- 
mon. When tobacco is used in large amount, the nerve of 
the eye suffers and a gradual loss of vision may ensue. 

479. Chewing and snuffing are so filthy that this objection 
alone should be sufficient to prevent the use of tobacco in these 
forms. Very many persons are injured by smoking. Boys 
who smoke cigarettes prevent their bodies from growing to a 
natural size. The habit of smoking has other objections. The 
smell of the tobacco becomes stale and clings to the hair and 
clothing, the breath becomes offensive and the teeth soiled. 
The craving for tobacco and for drink are very apt to go hand 
in hand. 



SYNOPSIS. 

Stimulants— Excite the system ; alcohol, tea, coffee, ammonia, etc. 

Narcotics — Benumb the system, relieve pain, and produce sleep ; 
opium, morphine, chloral, tobacco. 

Alcoholic Drinks : Beer, ale, porter, stout, cider, wine, liquors, 
cordials. 

Non-alcoholic Drinks : Ginger-ale, sarsaparilla, soda-water, lemon- 
ade, etc. 

Properties of Alcohol : 

1. Clear and colorless liquid. 

2. Resembles water, but lighter. 

3. Pleasant odor. 

4. Takes fire readily and burns with faint bluish flame, no 
smoke. 

5. Taste hot and burns mouth. 

6. Evaporates easily. 



220 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Uses of Alcohol : 

1. Dissolves oils and resins ; makes varnish. 

2. Extracts useful parts of leaves, bark, roots, and herbs 
forming tinctures. 

3. Making thermometers. 

4. Preserving vegetable and animal tissues. 
Fermentation : due to growth of minute living germs from the air. 

1. Acetous— changing alcohol to vinegar. 

2. Vinous — forming alcohol and carbonic acid gas from 
starchy or sugary fluids by aid of yeast, moisture, and warmth. 

How Alcohol is Made : 

1. Addition of yeast and water to starchy or sugary sub- 
stance. 

2. Moderate heat. 

3. Boiling to drive off alcohol. 
Varieties of Alcoholic Drinks : 

1. Beers, ales, porter, stout, and cider — contain two to six 
per cent, alcohol ; cider made from apples, the others from 
malt (barley). 

2. "Wines — contain eight to seventeen per cent, alcohol. 

White and red. 
Sweet and dry. 
Effervescent wines. 
Home-made wines. 

3. Liquors — contain one half alcohol. Made from grain vari- 
ously flavored. 

a. Wliiskey— rye or corn. 

b. Brandy — grapes. 

c. Bum — molasses. 

d. Gin — flavored with juniper. 

e. Absinthe — flavored with wormwood. 

4. Cordials — colored, clear liquids, contain large proportion 
of alcohol, flavored with peppermint, anise, fennel, orange, etc. 

General Effects of Alcohol : 

1. Not ordinarily a food. 

2. Intoxicating. 

3. Very common cause of crime. 

4. Morally objectionable — lowers moral sense, wastes money, 
causes neglect of family, etc. 



STIMULANTS AND NARCOTICS. 221 

5. Diminishes mental power. 

6. Diminishes muscular power. 

7. Diminishes warmth of body. 

8. Excites brain in an undesirable way and dulls the intel- 
lect. 

9. Lessens power to resist disease and recover from accidents. 

10. Habit very difficult to break off. 
Effects of Alcohol upon the Tissues of the Body : 

1. Irritates and hardens stomach and interferes with diges- 
tion of food ; dyspepsia. 

2. Causes nausea and vomiting. 

3. Irritates intestines. 

4. Causes heart to beat too rapidly and irregularly. 

5. Changes muscle to fat. 

6. Enlarges, then contracts liver. 

7. Blood-vessels become stiff, inelastic, and dilated. 

8. Veins become enlarged. 

9. Weakens the nerves and causes trembling. 

10. Causes loss of sight. 

11. Delirium tremens. 

Narcotics — Benumb the system ; relieve pain and produce sleep ; 
cause an artificial sleep, which lacks the refreshing qualities of nat= 
ural sleep. 

a. Opium : Brownish mass or powder ; comes from India and 
neighboring countries ; contains white crystals called mor- 
phine ; a poison. 

1. Useful only when prescribed by a physician. 

2. Morphine has same effect as opium. 

3. Dissolved in alcohol and water, known as laudanum. 

4. Persons often acquire the habit of taking it by mouth, 
smoking, or beneath the skin. 

5. The opium habit is very injurious, and is the most diffi- 
cult to break. 

6. As a result of the opium habit the health suffers very 
much ; the poor victims often end their lives in hospitals 
and lunatic asylums, or attempt suicide. 

b. Chloral: 

1. Occurs in white crystals. 

2. Often taken to produce sleep. 



222 ANATOMY, PHYSIOLOGY, AND HYGIISNE. 

3. Danger of habit, so that a person cannot sleep without 
it. 

4. Chloral habit causes nervousness and other bad effects 
upon system. 

5. Dangerous in increased dose. 
o. Tobacco: 

1. Used by American Indians when Columbus landed. 

2. Introduced into France in 1560 ; into England, by Sir 
Walter Ealeigh, in 1586. 

3. Leaf of plant grown and cultivated in United States 
and other countries. 

4. Used in smoking, chewing, and snuffing. 

5. Contains a poisonous principle called nicotine. 

6. Effects upon the system : 

(1.) Quieting effect and sense of repose in some }:>er- 
sons. 

(2.) Other persons no effect or disagreeable effect. 

(3.) Causes smoker's sore throat. 

(4.) Causes nausea and vomiting. 

(5.) Appetite suffers. 

(6.) Causes dyspepsia. 

(7.) Often causes palpitation of the heart. 

(8.) Often causes nervousness and trembling. 

(9.) May cause gradual loss of sight. 

7. Uncleanly habit ; hair and clothes smell of stale 
smoke ; breath becomes offensive ; teeth soiled. 

8. Chewing and snuffing are very filthy. 

9. Causes craving for alcoholic drink. 

10. Tobacco and alcohol habits usually associated. 
Cocaine : 

1. A new drug, used to relieve pain when dropped or 
painted on the surface, especially the eye. 

2. Stimulates and produces feeling of rest. 

3. Great danger of forming habit. 

4. Habit causes weakness of nervous system and symp- 
toms like those occurring with the opium habit. 

5. Habit may end in insanity. 



STIMULANTS AND NAKCOTICS. 223 



QUESTIONS. 

1. What are stimulants ? 2. Which are the most common ? 3. 
What is meant by alcoholic drinks ? 4. What is meant by non-alco- 
holic drinks ? 5. What examples of the latter can you give ? 6. 
What are the properties of alcohol? 7. What are the uses of alco- 
hol ? 8. What is fermentation ? 9. What are the two most common 
forms of fermentation ? 10. How is vinegar made ?- 11. How is al- 
cohol made ? 12. From what is the alcohol formed ? 13. What is 
necessary to produce alcoholic fermentation? 14. What is distilla- 
tion ? 15. What kinds of alcoholic drinks are there ? 16. How is 
beer made? 17. What is malt? 18. How is ale made? 19. How 
are porter and stout made ? 20. How is cider made ? 21. Y\ T hat per- 
centage of alcohol does each of these contain ? 22. From what is 
wine made? 23. About how much alcohol do wines contain? 24. 
Why are some wines white and others red ? 25. What is meant by a 
dry wine? 26. From what are the different liquors made? 27. How 
much alcohol do they contain ? 28. What are cordials ? 29. What 
is the danger in taking bitters and tonics too freely? 30. In what 
way may alcohol prove useful to the physician in treating disease ? 
31. Is alcohol ordinarily a food? 32. What is the meaning of the 
word intoxicating ? 33. W T hat influence has the use of drink upon 
crime? 34. Does alcohol increase the warmth of the body? 35. 
How can you prove to the contrary ? 36. Does alcohol increase 
muscular power? 37. What proof is there to the contrary? 38. 
What effect has alcohol upon the power of the brain ? 39. What 
effect has alcohol upon the stomach and intestines ? 40, upon the 
liver ? 41, upon the heart ? 42, upon muscular tissue ? 43, upon the 
blood-vessels? 44, upon the nerves ? 45, upon the membranes of the 
brain ? 46, upon the power to resist disease and to recover from ac- 
cidents ? 47. What is delirium tremens ? 48. What causes it ? 49. 
What are its symptoms ? 50. Why do patients sometimes die from this 
disease ? 51. What effect has alcohol upon the eyesight ? 52. What 
are the moral effects of alcohol ? 53. What can you say about the 
alcohol habit ? 54. What are narcotics ? 55. Which can you men- 
tion ? 56. Which are used most frequently for producing sleep ? 
57. What does opium look like? 58. What is morphine and from 
what is it derived? 59. Of what use are opium and chloral in sick- 



224 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

ness ? 60. What is laudanum ? 61. What is the morphine or opium 
habit? 62. How is this habit formed? 63. Why do these persons 
take this poison ? 64. What effects has the habit upon the health ? 
65. How does the habit end ? 66. What is chloral ? 67. What is it 
used for? 68. What is the chloral habit ? 69. What effect does this 
habit produce ? 70. What is cocaine? 71. Of what use is it ? 72. 
How does the oculist use it? 73. What is the cocaine habit? 74. 
Why is cocaine taken internally ? 75. What symptoms follow as a re- 
sult of this habit ? 76. What is very frequently the end ? 77. What 
is tobacco? 78. What is our earliest knowledge of tobacco? 79. 
When was it introduced into France? 80. When into England and 
by whom? 81. Where does it grow? 82. How is it used? 83. 
What effect has it upon the system ? 84. What advantage is claimed 
for it by some persons ? 85. What objections are there to smoking? 
86. What additional objections are there to chewing and snuffing? 



GLOSSAET. 



(The numbers following definitions refer to pages containing additional 
information. ) 



Ab do'men (Latin, abdere, to hide). The large cavity of the lower part 
of the trunk, below the diaphragm, in which the liver and the 
stomach, intestines, and other digestive organs are placed ; the 
belly, 17, 18, 34. 

Ab sorption (Latin, ab, and sorbere, to suck up). The process of suck- 
ing up fluids by means of the blood-vessels or lymphatics, 91. 

Ad'am's Ap'ple. The prominent angles of the larynx which can be 
seen and felt in the front of the neck. It is said to have been thus 
named from an old belief that the apple stuck in Adam's throat, 
thus causing this projection, 126. 

Al'co hol (Arabic, al hold, a powder to paint the eyebrows with). A 
colorless fluid, resembling water in appearance, which forms the in- 
toxicating portion of beer, wine, and spirits, 208, 216. 

Ali ment'a by Ca-nal (Latin, alere, to feed). The series of hollow 
organs in which the food is digested, or prepared for absorption by 
the blood. It comprises the mouth, pharynx, oesophagus, stomach, 
and intestines, 74, 75. 

A nat'o my (Greek, ana, up, and temnein, to cut). The study of the 
form and structure of the different parts of the body, 13. 

A ob'ta (Greek, aeirein, to lift up). The large artery which arises 
from the left ventricle of the heart and passes down along the back- 
bone, giving off branches in its course, 111, 112. 

Ap'o plexy (Greek, apo, awa} r , and plessein, to strike). A sudden loss 
of consciousness, due to the bursting of a blood-vessel in the 
brain, 117. 

A'que ous (Latin, aqua, water). Watery, 193, 194. 



226 GLOSSARY. 

A'que ous Htj'mor (Latin, humere, to be moist). The few drops of 
watery fluid which fill the space between the cornea and the lens of 
the eyeball, 193, 194. 

Art' tee, y (Greek, aer, air, and terein, to contain). A blood-vessel which 
conducts blood from the heart to the various tissues. The ancients 
believed that the arteries were filled with air ; hence the name, 100, 
112. 

At/ in cle (Latin, auris, the ear ; auricula, a small ear). The upper 
cavity of the heart on each side ; so named from its fancied resem- 
blance to a dog's ear, 108. 

Bi' ceps (Latin, bis, twice, and caput, head). A large and strong mus- 
cle on the front of the arm, serving to bend the forearm upon the 
arm ; so called because it is attached to the bone by two portions 
called heads, 51, 53, 54, 55. 

Br cus'pid (Latin, bis, twice, and cuspis, point). The name given to 
the fourth and fifth teeth on each side, on account of their possess- 
ing two elevations upon the crown, 77. 

Bile (Latin, Ulis, anger, bile). The gall ; the peculiar yellowish or 
greenish fluid, bitter to the taste, formed in the liver, and emptied 
into the commencement of the small intestine, 89. 

Bow'' el (Latin, botellus, a small sausage). The intestine ; the long 

hollow tube into which the partly-digested food passes from the 

stomach, 75, 85, 87. 

.„ , t (Greek, bronchos, windpipe). The first two divis- 

Bron'ohus P . ' , ._ ' . . . . . 

ions of the windpipe, one passing to each lung, 



Bron'chi (plural) , 186> 130 , i 33 . 

Bron'chi al. Relating to the bronchi ; bronchial tubes, the smaller 
branches of the bronchi in the substance of the lung, 126, 130, 132. 

Bun'ion. An enlargement and soreness of the great toe at the joint 
connecting it with the body of the foot, 25. 

Ca nine' (Latin, canis, dog). The sharp, pointed tooth on each side 
of the incisors ; so called because it is very prominent in the dog, 
77. 

Cap'il la ries (Latin, capillus, hair). The smallest blood-vessels, con- 
necting the arteries and veins ; so called on account of their mi- 
nute, "hair-like" size, 110, 112, 113. 

Cap'stj lar (Latin, capsula, a small box). A name used to qualify cer- 
tain ligaments which surround joints "like a box," 43, 44. 

Car bon'ic Acid Gas (Latin, carbo, coal). The gas which is present in 



GLOSS AKY. 227 

the air breathed out by animals ; it represents waste in animals, 
but serves as food for plants, 103, 110, 113, 134, 135, 209. 

Car niv'o rous (Latin, carnis, tlesh, and vorare, to devour). Subsisting 
largely or entirely on flesh, 64. 

Car'pus (Greek, carpos, the wrist). The collection of small bones, 
eight in number, forming the wrist, 20, 22, 35. 

Cartilage (Latin, cariilago, gristle). A solid elastic substance found 
in joints, in the nose and elsewhere ; gristle, 25, 43, 46, 187. 

Cell (Latin, cetta, a store-room). A small body, often rounded, form- 
ing one of the simplest parts of which the body is built up ; cells 
and fibres make up the greater part of the body, 16, 82, 89, 162. 

Cer'e bel'lum (Latin, diminutive of cerebrum, the brain). The little 
brain, placed beneath the back part of the rest of the brain, 160, 
161, 162, 164. 

Cer'e brum (Latin). The larger portion (seven-eighths) of the brain, 
160, 161, 162, 164. 

Ciiest (Latin, cista, a box). The upper cavity of the trunk inclosed by 
the breast-bone, ribs, and spinal column, and containing the heart 
and lungs, 17, 18, 20, 22, 33, 138. 

Ciilo'ral (Greek, chloros, pale green). A drug used to produce sleep, 
216, 217. 

Cho'roid (Greek, chorion, a membrane). The middle coat of the eye- 
ball, 193, 196. 

Cir cu la'tton (Latin, circulus, a ring). The course of the blood 
through the heart and blood-vessels of the body ; from heart to ar- 
teries, through capillaries to veins, back to heart, 100, 105, 109, 
110. 

Clav'i cle (Latin, clavicula, a little key, from clavis, key). The long, 
slender bone extending across the upper part of the front of the 
chest, the collar-bone, 20, 22, 32, 34. 

Clot. The dark-red, semi-solid mass which results when blood is 
withdrawn from the blood-vessels, 104. 

Co'ca ine (Spanish, coca, a Peruvian plant). A drug used to make cer 
tain parts insensible to pain, 218. 

Com bus'tion (Latin, comburere, to burn). A burning-up ; applied to 
the process taking place in the body by which the tissues are con- 
sumed, to be replaced by elements in the blood, 143. 

Corn (Latin, cornu, a horn). A small elevation due to thickening of 
the outer layer of the skin ; corns usually appear upon the toes and 
are caused by pressure from shoes which do not fit properly or are 
too tight, 25. 



228 GLOSSARY. 

Cor'ne a (Latin, cornu, a horn). The transparent membrane which 
forms the front of the eyeball, 193. 

Coe/o nal (Latin, corona, crown). A name given to the suture which 
unites the frontal with the parietal bones, because the crown of a 
king rests in part upon this line, 42. 

Coe/pus cles, Blood (Latin, corpus, a body ; corpusculum, a small 
body). The small bodies, some red, some white, found floating in 
the fluid part of the blood, 100, 101. 

Cos met'ic (Greek, kosmos, ornament). Preparations which when ap- 
plied to the skin are supposed to increase its beauty, 182. 

Cra'ni tjm (Latin). That portion of the skull which incloses the brain , 27. 

Crown (Latin, corona, a crown). The top of the skull, 16. Also the 
part of the tooth which projects into the mouth, 76. 

Crys'tal line (Latin, crysiallum, a crystal). Like glass ; applied to the 
lens in the interior of the eye on account of its transparent proper- 
ties, 193, 194. 

Dan'druff. The small scales, corresponding to the outer layer of the 

skin, which fall off the scalp, 177. 
Deaf' mute. A person who is deaf and dumb, 205. 
De lir'ium (Latin, delirare, to wander in mind). A condition in which 

the ideas of a person are wild and wandering, 169, 214. 
De lir'ium Tre'mens (Latin, tremere, to tremble). The condition of 

being out of the mind, which results from over-indulgence in alco- 
holic drink, 169, 214. 
Den'tine (Latin, dens, a tooth). The hard material which forms the 

main part of the tooth between the pulp within and the enamel on 

the surface, 76. 
Di'aphragm (Greek, diaphrassein, to divide by a partition). The sheet 

of muscular tissue which separates the chest from the abdomen, 34, 

56. 
Digest' (Latin, dirjerere, to separate). To separate the food into nutri- 
tious juices which can be absorbed by the system and matters which 

are cast off, 74, 91. 
Dislo ca'tion (Latin, dislocare, to put out of place). The separation, 

by accident, of the ends of bones forming a joint, 44. 
Drum Mem'brane. The small sheet of tissue which separates the outer 

from the middle ear, and serves to transmit sounds to the interior 

of the ear, 203, 205. 
Duct (Latin, ducere, to lead). A narrow tube, such as the bile-duct, 94, 

nasal duct, 197, 198. 



GLOSSARY. 229 

Duo de'num (Latin, duodeni, twelve each). The first portion of the 

small intestine ; so called because its length is about twelve fingers' 

breadth, 75, 85. 
Dyspep'sia (Greek, dys, difficult, and peptein, to digest). A disordered 

state of the organs of digestion giving rise to difficult or painful 

digestion, 78, 92, 214. 

En am'el. The hard layer which covers the crown of the tooth, 76. 

Epi dem'ic (Greek, epidemos, among the people). A disease which at- 
tacks a large number of persons of one neighborhood at the same 
time, 70. 

Epi glot'tis (Greek, epi, above, and glotta, the tongue). A leaf- shaped 
piece of cartilage which covers the entrance to the larynx during 
swallowing, 127. 

Eu sta'chi-an Tube. The tube which leads from the throat to the 
middle ear, so called from the physician who first described it, 204. 

Ex pi-ra'tion. The act of breathing out, 125, 128. 

Expire' (Latin, ex, out, and spirare, to breathe). To breathe out, 125, 
128. 

Faint'ing. Loss of consciousness, due usually to an interference with 

the circulation, 114. 
Fang. The long, pointed end or root of a tooth, 76, 77. 
Farina'ceous (Latin, farina, flour). Containing starch ; starchy, 64. 
Far'-sigiited. Having one of the forms of defective sight, 199. 
Fe'mur (Latin). The thigh-bone, 20, 22, 35, 36. 
Fermen ta'tion (Latin, fervere, to be boiling hot). The change by 

which starch or sugar in a liquid is converted into alcohol and a 

gas, 209, 210. 
Fi'bre (Latin, fibra, a thread). One of the tiny threads of which a large 

portion of the body is formed, 16, 47. 
Fib'ula (Latin, fibula, a clasp). The outer, long, slender bone of the 

leg, 20, 22, 36. 
Flesh'y. Applied to animal food, especially meat, in distinction from 

vegetable food, 47, 64. 
Fract'ure (Latin, frangere, to break). The breaking of a bone, 25, 26. 
Front'al (Latin, from, the forehead). Belonging to the forehead, 22, 

27, 29. 
Func'tion (Latin, functio, performing). The special work of any or- 
gan of the body, 15, 154. 

Gall. The bile, 89. 



230 GLOSSARY. 

Gas'tric (Greek, gaster, the stomach). Belonging to the stomach, 82. 

Gastric Juice. The fluid secreted by the stomach, which digests 
fleshy food, 82, 83. 

Gel'a tin (Latin, gelare, to congeal). An animal substance found in 
bones, cartilage, and other tissues, which dissolves in boiling water, 
and forms a firm jelly upon cooling, 24 

Gland (Latin, glans, an acorn). An organ which separates certain 
substances from the blood, 78, 79, 197. 

Gout (Latin, gutta, drop). A disorder of the system in which one of 
the prominent symptoms is a painful affection of the joints, 90. 

Gran'u lar Lids (Latin, granum, grain). A contagious affection of 
the eyelids, so called because the lids, when turned out, often pre- 
sent the appearance of being studded with small grain-like bodies, 
199. 

Gris'tle. Cartilage, 25, 43, 46, 187. 

Groin. The depression on each side between the abdomen and thigh, 
just below the hip, 17, 18. 

Gul'let (Latin, gula, throat). The tube between the throat and stom- 
ach, serving for the passage of food and drink ; the oesophagus, 75, 
79, 80, 129. 

Hang'nail. A small flake of skin which hangs from the side or root 

of a nail, 183. 
Hem'i spheres (Greek, liemi, half, and sphaira, a sphere). The halves 

into which the cerebrum is divided, 158, 161. 
Hem'or rhage (Greek, haima, blood, and regnumi, to burst). The es- 
cape of blood from the blood-vessels ; any bleeding, 116. 
Herbiv'o rous (Latin, Jierba, herb, and xorare, to devour). Subsisting 

on vegetable food, 64. 
Hip. The projection on each side of the body just above the thigh, 

formed by the hip-bone, 17, 18. 
Hops. A plant, the flowers of which are used in flavoring beer, 211. 
Hu'man (Latin, homo, man). Relating to man, 13. 
Hu'merus (Latin). The thigh-bone, 20, 22, 34. 
Hu'mor (Latin, liumere, to be moist). An animal fluid ; especially the 

fluid contents of the eyeball, 193, 194. 
Hy'giene (Greek, Ilygeia, the goddess of health). The science which 

treats of the preservation of health and the prevention of disease, 13. 

In ci'sor (Latin, incidere, to cut in). The four front teeth in both jaws ; 
they have sharp, chisel-like edges, 77. 



GLOSSARY. 231 

In'dex Fin'ger (Latin, indicare, to point out). The forefinger; the 
finger next to the thumb, 18, 22. 

In di gest'i-ble (Latin, in, not, and digerere, to separate). Not easily 
converted by the organs of digestion so as to be fit for absorption by 
the blood and tissues, 84. 

In di ges'tion (Latin, in, not, and digerere, to separate). A condition 
in which the food is not properly digested, or digested with diffi- 
culty, 78, 92. 

Inspire' (Latin in, in, and sjiirare, to breathe). To draw in breath, 
125. 

In spi ra'tion (Latin, in, in, and spirare, to breathe). The act of in- 
spiring or drawing in breath, 125. 

In'step. The raised portion of the foot near the ankle, 17, 18, 36. 

In-tel'li-gence (Latin, inielligere, to understand). The power which 
enables us to judge and understand; 163. 

In tes'tine (Latin, intus, on the inside). The hollow tube which fills 
the greater part of the abdomen, and forms the continuation of the 
digestive organs beyond the stomach ; the bowels, 75, 85. 

In tox'i cating (Latin, toxieum, an arrow poison). Making drunk; 
capable of bringing under the effects of alcohol, 208, 212, 215. 

In vol'un ta ry (Latin, in, not, and voluntas, will). Not dependent 
upon the will, 50, 133. 

I'ris (Latin, iris, the rainbow). The colored membrane in the front 
portion of the eye perforated in its centre by the pupil, 193, 194. 

Jaun'dice (Latin, galbus, yellow). The yellowish discoloration of the 

skin and of the white of the eye, due to bile being present in the 

blood, 89. 
Joint (Latin, jungere, to bind together). The place of meeting or union 

of two or more bones, 41, 42, 43, 44. 
Judgment (Latin, judicare, from jus, law, and dimre, to proclaim). 

The faculty of judging or deciding correctly, 163. 

Kidney. An important organ placed in the back part of the abdom- 
inal cavity ; it separates certain refuse materials from the blood. 
There are two kidneys, 145. 

Lach'rymal (Latin, lacrima, a tear). Forming tears, 29, 197. 
Lacfi'rymal Duct. The small canal which conveys the tears from 

the eye to the interior of the nose, 197. 
Lach'rymal Gland. The small organ, placed just above the eye, 

which produces the tears, 197. 



232 GLOSSARY. 

Lac'teals (Latin, lac, milk). The small vessels (part of the lym- 
phatics) which carry the nutritious juices representing the digested 
food, from the intestines to the blood, emptying into a large vein of 
the neck, 91, 118, 119. 

Lam'bdoid (Greek letter lambda, A). The name given to the suture 
which connects the occipital with the parietal bones, on account of 
its resemblance in shape to the Greek letter lambda, A, 42. 

Larynx (Greek, larugx, a whistle). The upper part of the air-passage 
in which the voice is produced, 125, 126, 132. 

Lean (Latin, lenis, soft, moderate). Thin, devoid of fat, 48. 

Lens (Latin, lens, a lentil). A transparent body with curved surfaces, 
which influence the course of rays of light. The lens of the eye is 
the transparent body placed just behind the iris and pupil, which 
causes images to fall upon the retina or nervous layer of the eye- 
ball, 193, 194. 

Lig'a ment (Latin, ligare, to bind). The tough bands or sheets of tis- 
sue which cover the joints and bind the ends of the bones together, 
43, 44, 46. 

Limbs. The extremities of the human body attached to the trunk on 
each side, above and below ; there are two upper and two lower 
limbs, 18. 

Liq'uor (Latin, liquere, to be liquid). A name given to strong alcoholic 
fluids, such as whiskey, brandy, rum, etc., 211. 

Little Finger. The smallest finger ; situated on the opposite side of 
the hand from the thumb, 18. 

Lungs. The organ of breathing, occupying the greater part of the 
cavity of the chest, 130, 131, 132, 145, 149. 

Lymph (Latin, lympha, pure water). The colorless or white fluid con- 
tained in the lymphatics, 117, 118. 

Lymphat'ics (Latin, lympha, pure water). The small vessels which 
run from the tissues and finally empty into two large veins in the 
neck ; contain lymph, 117, 118. 

Mag'nified (Latin, magnus, great, and facere, to make). Made to ap- 
pear larger than in reality, 101. 

Ma'lar (Latin, mala, the cheek). The bone which forms the promi- 
nence of the cheek, 22, 29, 30. 

Malt. Sprouting barley which has been dried by heat so as to change 
its starch into sugar ; it is used in brewing beer, 211. 

Mar'row. A soft, fatty substance contained in the central cavity of 
bones, 24. 



GLOSSARY. 233 

Me dul'la (Latin, medulla, marrow, pith). The portion of the brain 
which connects it with the spinal cord, 160, 161, 162, 164. 

Metacarpus (Greek, meta, beyond, and karpos, the wrist). That 
part of the skeleton of the hand between the wrist and the fingers, 
20, 22, 35. 

Meta tar' sus (Greek, meta, beyond, and tarsos, ankle). That part of 
the skeleton of the foot between the heel and the toes, 20, 22, 36. 

Mi'cro scope (Greek, mikros, small, and skopein, to view). An optical 
instrument, consisting of a combination of lenses, used to view ob- 
jects which are too small to be seen by the naked eye, 101. 

Mid'dle Finger. The finger placed midway between the thumb and 
little finger ; the third finger, 18. 

Min'er al (Latin, mina, amine). Derived from the inorganic or life- 
less world ; such as the rocks, 64. 

Mo'lars (Latin, molere, to grind in a mill). The rear three teeth in 
both jaws, used in grinding the food into small particles, 77. 

Mor'phine (Greek, Morpheus, the god of sleep). A white substance 
which constitutes the narcotic principle in opium, 216. 

Mu'cous Mem'brane (Latin, mucosus, from mucus, slime, and mem- 
brana, a skin). The soft layer of tissue which lines the alimentary 
and breathing channels ; secretes mucus, 81. 

Mucus (Latin, mucus, slime). A slippery substance secreted by the 
mucous membranes to keep them moist, 82. 

Mus'cles (Latin, musculus, a muscle). The fleshy organs which move 
the various parts of the body, 46, 47. 

Nar cot'ic (Greek, narke, numbness). A drug which relieves pain and 
produces sleep ; when given in large quantity, produces insensi- 
bility and even death, 208, 215. 

Na'sal (Latin, nasus, the nose). Pertaining to the nose, 22, 29, 30, 
198. 

Near-sighted. A form of weak sight in which objects can only be 
seen clearly when held very close, 199. 

Nerves (Latin, nervus, a nerve). The thread-like bundles of fibres 
which run from the brain and spinal cord to different parts of the 
body and establish communication, 52, 157, 162, 166. 

Ni'tro gen (Latin, nilrum, nitre, and genere, to produce). The gas 
which forms four-fifths of the atmosphere ; serves to dilute the 
oxygen, 102. 

Nos'tril. One of the two oval apertures at the front of the nose 
through which air is drawn, 187. 



234 GLOSSARY. 

Oc'ci put (Latin, oc, back, and caput, the head). The hind part of the 

head or of the skull, 20, 22. 
Oc cip'i tal (Latin, oc, back, and caput, the head). Referring to the 

back part of the head, 27, 29. 
Oc'u list (Latin, oculus, the eye). One who treats diseases of the eye, 

196. 
(E soph'a gits (Greek, oiso (future of), to carry, and phagein, to eat). 

The passage for food, leading from the throat to the stomach, 75, 

79, 80, 129. 
O'pi UM. A narcotic drug obtained from the fruit of the poppy-plant, 

216. 
Op'tic (Greek, opticus). Pertaining to sight. Optic nerve, the nerve of 

sight, 193, 196. 
Orb its (Latin, orbis, a circle). The cavities in which the eyes are 

placed, 30, 193. v 

Or'gan (Latin, organum, an organ). A part of the body which per- 
forms some special work ; the eye is the organ of sight, 15. 
Ox'y gen (Greek, oxus, acid, and genein, to produce). An important 

gas which forms one-fifth of the atmosphere, and serves to sustain 

life, 102, 103, 110, 134, 135, 145. 

Pan'cre as (Greek, pan, all, and Jcreas, flesh). An important organ of 
digestion, situated in the abdominal cavity and pouring its secre- 
tion, the pancreatic fluid, into the small intestine, 75, 90. 

Pa ral'y sis (Greek, pam, beside, and luein, to loosen). Loss of the 
power of moving a greater or lesser number of muscles, 53. 

Par'alyzed (Greek, para, beside, and luein, to loosen). Affected with 
loss of the power of moving a greater or lesser number of the mus- 
cles, 53. 

Paei'etal (Latin, paries, a wall). A name given to the two bones 
which form the roof of the skull, 27, 29, 42. 

Parot'id (Greek, para, beside, and ous, the ear). A gland situated be- 
low and in front of the ear ; secretes part of the saliva, 78. 

Pa tel'la (Latin, patina, a pan). The knee-pan, 20, 22, 36. 

Pec'to kalis (Latin, pectus, the breast). The triangular muscle on 
each side of the front of the chest, which draws the arm inward, 54, 
55. 

Pel'vts (Latin, pelvis, a basin). The bony basin at the lower part of the 
trunk to which the thigh-bones are attached, 22, 32. 

Pep'sin (Greek, jiepsis, digestion). A substance present in the gastric 
juice, which digests fleshy food, 83. 



GLOSSARY. 235 

Peri car'di um (Greek, peri, around, and kardia, the heart). The sac 

which surrounds the heart, 107. 
Peri os'te um (Greek, peri, around, and osteon, a bone). A tough 

membrane closely covering the bones, 24. 
Peritone'um (Greek, peri, around, and teinein, to stretch). The 

smooth membrane which covers the abdominal organs and lines the 

cavity of the abdomen, 81, 86. 
Per spi ra'tion (Latin, per, through, and spirare, to breathe). The 

watery fluid given off from the skin ; when visible it is called sen- 
sible ; when invisible, insensible. The sweat, 149, 178. 
Phalan'ges — Plural of phalanx (Greek, phalanx, a rank). The small 

bones forming the fingers and toes, 20, 22, 35, 36. 
Phar'ynx (Greek, pharugx, the throat). The cavity at the back of the 

mouth through which the food passes on its w\ay to the oesophagus 

or gullet ; the throat, 75. 
Physi ol'o gy (Greek, phusis, nature, and logos, a discourse). The 

study of how beings live, 13. 
Plas'ma (Greek, plassein, to mould). The liquid part of the blood, 100, 

102. 
Pleura (Greek, pleura, the side). The smooth membrane which cov- 
ers the lungs and lines the cavity of the chest, 133. 
Pores (Latin, porvs, a passage). The minute openings in the skin 

through which the perspiration escapes, 145, 149, 178, 181. 
Pul'mo na ry (Latin, pulmo, a lung). Pertaining to the lungs, 109. 
Pulp (Latin, pulpa, pulp). The soft material which fills the central 

space in the teeth, 76. 
Pulse (Latin, pulsus, the pulse). The beating of the arteries, 113. 
Pupil (Latin, pupilla, pupil). The opening in the iris through which 

light passes into the interior of the eye, 194. 
Py lo'rus (Greek, puloros, a gate-keeper). The opening in the stomach 

by which food passes into the intestines, 75, 80, 85. 

Ra'di us (Latin, radius, a rod). The outer bone of the forearm , 20, 22, 34. 

Rea'son (Latin, ratio, reason). The power by which we distinguish 
right from wrong and are able to employ proper means for the at- 
tainment of particular ends, 163. 

Re'flex Action (Latin, re, back, and flectere, to turn). Actions ex- 
cited without our being conscious of them, 166. 

Re spire' (Latin, re, again, and spirare, to breathe). To breathe, 125. 

Respi ra'tion (Latin, re, again, and spirare, to breathe). The act of 
breathing, 125. 



236 GLOSSARY. 

Ret'ina (Latin, rete, a net). The innermost or nervous layer of the 
eyeball which receives the impressions of sight, 193, 196. 

Rib. One of the long, slender bones inclosing the chest, 20, 30, 33. 

Ring Finger. The finger next to the little finger, upon "which rings 
are usually worn, 18. 

Sag'it tal (Latin, sagiiia, an arrow). Pertaining to an arrow ; a name 
given to the suture which unites the parietal bones, because it meets 
the coronal suture as an arrow meets the bow, 42. 

Sa li'va (Latin, saliva, spittle). The liquid secreted by the glands near 
the mouth, emptied into this cavity and serving to keep the mouth 
moist and to form a mass with the food ; the spittle, 78, 190. 

Sal'i va ry. Pertaining to saliva or spittle, 78. 

Scalp (Latin, scalpere, to carve). The skin covering the top of the 
head, 17. 

Scap'u la (Latin). The shoulder-blade, 20, 22, 32, 34. 

Scarf' skin. The outer layer of the skin, 177. 

Scent (Latin, sent/ire, to smell). Odor ; smell, 189. 

Sclerot'ic (Greek, skleros, hard). The firm, white, outer layer of the 
eyeball, 193. 

Sensa'tion (Latin, sentire, to feel). Feeling caused by external ob- 
jects. Nerves of sensation are those which carry impressions of 
touch, pain, heat, etc., from the various organs of the body to the 
brain, 166, 176. 

Senses (Latin, sentire, to feel). The faculty of obtaining information 
of the exterior world by means of certain organs ; the five senses 
are, feeling, seeing, hearing, smelling, and tasting, 175. 

Sen si tive (Latin, sentire, to feel). Having a high degree of feeling, 176. 

Skel'e-ton (Greek, shellein, to dry up). The system of bones which 
constitutes the framework, 20, 21, 22, 47. 

Skull. The bones of the head taken collectively, 27, 28, 29. 

Sole (Latin, solea). The under surface of the foot, 17, 18, 36. 

Sol'tj ble (Latin, solvere, to dissolve). Capable of being dissolved in a 
fluid. 

Spe'cial Senses (Latin, specialis, a particular kind). The sense of 
taste, smell, sight, and hearing, as distinguished from the general 
one of feeling, 175. 

Spinal (Latin, spina, the spine). Relating to the spine or backbone. 
Spinal canal, the canal running through the back part of the back- 
bone or spine, in which is contained the soft bar of nervous tissue 
called the spinal cord, 22, 30, 32, 157, 164, 165. 



GLOSSAKY. 237 

Spleen (Latin, splen). A large, flat body, composed largely of blood, 
placed on the left side of the abdominal cavity, 75, 93. 

Squint. The condition of being cross-eyed, 195. 

Starch. The white grains found in wheat, potatoes, and many other 
plants, 64, 65. 

Ster'num (Greek, sternon, the breast). The breast-bone, 20, 22, 32, 34. 

Stim'u lant (Latin, slimulare, to incite). Anything which produces an 
increase of action in the system or any part of it, 66/208. 

Stom'acii (Greek, stoma, an entrance). The receptacle for the food, 
placed between the lower end of the gullet and the beginning of the 
intestines, 75, 80, 81. 

Sub lin'gual (Latin, sub, under, and lingua, the tongue). Situated 
under the tongue. Sublingual glands, two salivary glands placed 
underneath the tongue, 79. 

Sub max'il la ry (Latin, sub, under, and mala, jaw). Situated beneath 
the jaw. Submaxillary glands, two salivary glands placed under- 
neath the lower jaw, 79. 

Sut'ure (Latin, suere, to sew). The line of union between the bones 
of the skull, 41, 42. 

Syn o'vi al (Latin, ovum, an egg). Relating to the fluid found in 
joints. Synovial fluid, the fluid secreted in joints to permit of easy 
motion. It is formed by a sac known as the synovial membrane, 43. 

Sys'tem (Latin, sysiema). A collection of parts of the body performing 
the same function ; for instance, all the arteries of the body taken 
collectively are known as the arterial system. The term system is 
also used to denote the body as a whole, 155. 

Tar'sus (Greek, tarsos, the ankle). The solid, hind part of the foot 
which is joined to the leg, 20, 22, 36. 

Tem'ple (Latin, tempus, time). A spot on the side of the head, just in 
front of the ear, so called because the hair begins to turn gray in 
this situation, at the approach of age, 28. 

Tempo ral (Latin, tempus, time). Pertaining to the temple, 28, 29, 55. 

Ten'don (Latin, tenders, to stretch). The strong, fibrous part of a mus- 
cle by which it is attached to surrounding parts, especially bone, 48, 

Ther mom'e ter (Greek, thermos, hot, and metro n, measure). An in- 
strument used to measure the intensity of heat, 146. 

Thigh. The thick, fleshy portion of the lower extremity, between the 
lower end of the trunk and the knee, 17, 18. 

Tho'rax (Greek, thorax, a breast- plate). The chest, 18, 20, 22, 33. 

Thumb. The short, thick finger ; the first from the outer side, 18, 22. 



238 GLOSSARY. 

Tib'i a (Latin). The inner bone of the leg, 20, 22, 36. 

Tis'sue (Latin, texere, to weave). A form of material of the bod}', 
composed of various elementary substances, such as cells, fibres, 
nerves, blood-vessels, etc. , closely connected with each other, 15. 

To bac'co (Indian, tabaco, the tube, or pipe, in which the Indians smoked 
tobacco). A plant much used for smoking, chewing, and snuffing, 
117, 219. 

Tra'che a (Greek, trachvs, rough). The windpipe ; the canal which 
conveys air to the lungs, 126, 129, 132. 

Train (Latin, trahere, to draw). To prepare the body for extraordi- 
nary feats of strength or endurance, 58, 213. 

Tri'ceps (Latin, tria, three, and caput, head). The large muscle on the 
back of the arm ; so called because it is formed above of three por- 
tions, 53, 55. 

Trunk (Latin, truncus, trunk). The central part of the body, to which 
head and limbs are attached, 18. 

Tu'bule (Latin, tubus, a pipe). A small tube, 82, 83. 

Ul'na (Latin, ulna, elbow). The inner bone of the forearm, 20, 22, 34. 

Valve (Latin, valva, a folding-door). A lid or cover so formed as to 

open in one direction and close in the other, 111, 112. 
Ve'ge table (Latin, vegetare, to enliven). Relating to plants, 64, 66. 
Vein (Latin, vena, vein). One of the blood-vessels which receives 

blood from the capillaries and returns it to the heart, 99, 112, 113. 
Venti la'tion (Latin, veniulus, a slight wind). The act of removal of 

impure air and admission of pure air, 135. 
Ven'tri cles (Latin, veniricidus, dim. of venter, the belly). The two 

lower and larger cavities of the heart, 107, 108. 
Ver'te bra (Latin, veriere, to turn). One of the bones which make up 

the spine or backbone, 31. 
Vit're ous (Latin, vitrum, glass). Like glass. Vitreous humor, the 

transparent, jelly-like substance which fills the eyeball, behind the 

lens, 194. 
Vo'cal (Latin, vox, voice). Relating to the voice-sounds ; vocal cords, 

the bands of membrane existing in the larynx, which produce the 

voice-sounds by their vibration, 127, 128, 129. 
Vol'un ta ry (Latin, voluntas, will). Produced by an act of the will, 49. 

Wind'pipe. The passage by which air reaches the lungs. The trachea, 

126, 129, 132. 
Yeast. A substance added to starchy or sugary liquids to produce 

fermentation, 67, 211. 



INDEX. 



Abdomen, 17, 18, 34, 225 
Absinthe, 211 
Absorption, 91, 225 
Acetous fermentation, 210 
Achilles, tendon of, C6 
Adam's apple, 126, 225 
Air, 102 
changes produced in, by breath- 
ing, 134, 135 
impure, effects of, 135 
purification of, 135 
Air-passages, 129, 130, 186 
Air-spaces, 132 
Air- vesicles, 132 
Alcohol, 208, 216, 225 
and digestion, 93, 214 
effects of, on arteries, 117, 214 
on brain, 213 

on the circulation, 116, 214 
on the heart, 116, 214 
on the liver, 90, 214 
on the muscles, 57, 214 
on the nervous system, 168, 

214 
on the skeleton, 26 
on the stomach, 84, 93, 214 
on the system, 212 
on the tissues, 213 
manufacture of, 210 
moral effects of, 215 



Alcohol, properties of, 208 

questions on, 223 

synopsis of, 219 

uses of, 208 
Alcoholic drinks, 208 

effects of, on system, 212 

manufacture of, 210 

varieties of, 210 
Alcoholic fermentation, 210 
Alcoholic habit, 215 
Ales, 211 

Alimentary canal, 74, 75, 225 
Anatomy, 13, 225 
Animals and plants, differences 
between, 15, 64 

similarity in structure of, 154 
Animals, carnivorous, 64 

difference in food of, 64 

herbivorous, 64 

warm-blooded and cold-blooded, 
146 
Ankle, 17, 18, 

bones of, 20 
Anvil, 203 
Aorta, 111, 112, 225 
Apoplexy, 117, 225 
Apple, Adam's, 126, 225 
Aqueous humor of eye, 193, 194i 

226 
Arch of foot, 17, 18, 86 



240 



INDEX. 



Arm, 17, 18 

bone of, 20, 22, 34 
Arm-pit, 17, 18 
Arteries, 99, 112, 226 

effects of alcohol on, 117 
Artery, pulmonary, 109 
Auricles of heart, 108, 226 

Backbone, 31 
Ball-and socket joint, 44 
Bathing, 181 . 

after meals, 92 
Baths, cold, 181 

Russian, 182 

Turkish, 182 

warm, 181 
Beats of heart, 108 
Beef, 67 
Beers, 211 
Beings, living, 14 
Biceps, 51, 53, 54, 55, 226 
Bicuspid teeth, 77, 226 
Bile, 89, 226 

action of, 89 
Birds, blood of, 102 
Bitters, 212 
Bleeding, 115 

treatment of, 115, 116 
Blindness, 196 
Blood and circulation, 100 

questions on, 122 

synopsis of, 119 
Blood and tissues, changes in, pro- 
duced by breathing, 134 
Blood, appearance of, 100 

clotting of, 104 

color of, 100 

composition of, 100 

course of, 108, 109, 110 

difference between, in arteries 
and in veins, 100, 103 



Blood, importance of, 100 

purification of, 110 

serum of, 104 
Blood-clots, value of, 104 
Blood-corpuscles, 100 
Blood-globules, 100, 101 

red, 101 
use of, 102 

white, 101 
Blood-heat, 146 
Blood of other animals, 102 
Blood-plasma, 100, 102 
Blood-vessels, 99, 112 
Body, parts of, 15, 16, 17 

subdivisions of, 15, 16, 17 
Body-heat, 143, 146 

in sickness, 147 

regulation of, 147 
Bone, composition of, 24 

structure of, 24 
Bones, forms of, 23 

number of, 23 

uses of, 21 

of the cranium, 27 

of the ear, 203 

of the face, 27, 28 

of the head, 27 

of the lower limbs, 35 

of the skull, 27 

of the trunk, 30 

of the upper limbs, 34 
Bowels, 75, 85, 226 
Brain, 156, 158, 159, 160, 164 

coverings of, 158 

divisions of, 160, 164 

functions of, 163 

size of, 158 

training of, 163 

weight of, 158 
Brandy, 211 
Bread, 67 



INDEX. 



241 



Breast-bone, 20, 22, 30, 32, 34 
Breathing and smelling channels, 

186 
Breathing, changes which it pro- 
duces in blood and tissues, 
134 
changes which it produces in the 

air, 134 
effect of tight clothing upon, 138 
frequency of, 133 
involuntary nature of, 133 
movements of chest in, 133 
mouth, 133 
organs of, 125 
synopsis of, 139 
questions on, 141 
Bridge of nose, 17 
Bronchial tubes, 126, 130, 132, 226 
Bronchi, 126, 130, 132, 226 
Bronchus, left, 130, 132 

right, 130, 132 
Brows, 192, 193 
Bunion, 25, 226 
Burning of fuel, results of, 144 
Butter, 66, 67 

Calf of leg, 17 

Canal, alimentary, 74, 75 

of ear, 202, 203 

from liver and gall-bladder, 87 

from pancreas, 88 

spinal, 30, 31 
Canine teeth, 77, 226 
Capillaries, 110, 112, 113, 226 
Capsular ligaments, 43, 44, 226 
Carbonic acid gas, 103, 110, 134, 

135, 209, 226 
Care of circulation, 116 

of ears, 206 

of eyes, 198 

of hair, 183 



Care of muscles, 56 

of nails, 183 

of skin, 180 

of teeth, 78 
Carnivorous animals, 64, 227 
Carpus, 20, 22, 35, 227 
Cartilage, 25, 43, 46*, 227 
Casting off refuse materials, 145 
Cavities of heart, 107 
Cells, 16, 227 

of brain, 162 

of liver, 89 

of stomach, 82 
Cerebellum, 160, 161, 162, 164, 227 
Cerebrum, 160, 161, 162, 164, 227 

gray and white portions of, 161 

hemispheres of, 159, 161 
Cheek, 17 

bone of, 22 
Cheese, 68 
Chest, 17, 18, 20, 22, 33, 227 

deformed, 25, 138 

movements of, in breathing, 133 

muscle of, 55 
Chewing-gum, effects of, 79, 92 
Chin, 17 " 
Chloral, 216, 227 

habit, 217 
Chocolate, 66 

Choroid coat of eye, 193, 196, 227 
Cider, 211 
Circulation, 100, 105, 110, 227 

and exercise, 116 

care of, 116 

course of, 109, 110 

discovery of, 108 

effects of alcohol on, 116 

effects of tobacco on, 117 

rapidity of, 114 

through lungs, 109, 110 
Clavicle, 20, 22, 30, 32, 34, 227 



242 



INDEX. 



Clot, 104, 227 
Clothing, 147, 148, 182 

woollen, 147 
Clotting of blood, 104 
Coats of eye, 193 

of intestines, 85 

of stomach, 80 
Cocaine, 218, 227 

habit, 218 
Coccyx, 31 
Coffee, 66, 208 

effects of, on nervous system, 
169 
Cold-blooded animals, 146 
Cold, effects of, 149 

in head, 188 
Collar-bone, 20, 22, 30, 32, 34 
Color of hair, 180 

of skin, 177 
Column, spinal, 30 
Combination of all forms of food, 

necessity for, in man, 66 
Combustion, 143, 227 
Contraction of muscles, 51 
Cooking, methods of, 68 
Cool, keeping, in summer, 148 
Cord, spinal, 31, 52, 157, 164, 165 

functions of, 166 

injuries to, 165 

membranes of, 165 

structure of, 165 
Cordials, 212 

Cords, vocal, 127, 123, 129 
Cornea, 193, 227 
Corns, 25, 227 
Coronal suture, 42, 228 
Corpuscles, blood, 100, 228 
Cosmetics, 182, 228 
Course of blood, 108 

of inspired air, 125 
Cranial nerves, 162, 228 



Cranium, bones of, 27, 228 

method of union 28, 29 
Cream, 67 
Cross-eye, 195 
Crown of head, 16, 228 

of tooth, 76 
Crystalline, 193, 194, 228 

Dandruff, 177, 228 
Deaf-mutes, 205, 228 
Deformed chest, 25, 138 

foot, 26 
Delirium tremens, 169, 214, 228 
Dentine, 76, 228 
Diaphragm, 34, 56, 228 
Digestion, 74, 91, 228 

and excitement, 92 

effects of alcohol upon, 93 

effects of tobacco on, 93 

habits which are injurious to, 
92 

of fatty food, 87, 91 

of fleshy food, 82, 87, 91 

of starchy food, 79, 87, 91 

organs of, 74, 75 

questions on, 97 

synopsis of, 93 
Discovery of action of the stomach, 
84 

of circulation, 108 
Dislocations, 44, 228 
Distillation, 210 
Dress, effect of, on skeleton, 25 
Drinking-water, 69 

from wells, 69 

impure or poisoned, 69 

poisoning by lead, 71 

purification of, 70 ■ 

purity of, 69 
Drink, alcoholic, 208 

effects of, 212 



INDEX. 



243 



Drum of ear, 202, 203 
Drum-membrane of car, 203, 205, 

228 
Duct, nasal, 197, 198, 228 

tear-, 197, 198 
Duodenum, 75, 85, 228 
Dyspepsia, 78, 214, 229 

Ear, bones of, 203 

canal of, 202, 203 

care of, 206 

communication with throat, 203 

drum of, 203, 205 

drum-membrane of, 202, 205 

internal, 204 

middle, 202 

outer, 202 

parts of, 202 

questions on, 207 

synopsis of, 206 
Ear-wax, 202, 206 
Easily digested food, 84 
Eating excessively, 92 

quickly, 92 
Eggs, 68 
Elbow, 17, 18 
Elbow-joint, 22 
Enamel of tooth, 76, 229 
Epidemics, 70, 229 
Epiglottis, 127, 191, 229 
Eustachian tube, 204, 229 
Excessive eating, 92 
Excitement and digestion, 92 
Eye, 175, 192, 193 

care of, 198 

choroid coat of, 193, 196 

coats of, 193 

fluids of, 193, 194 

good light for, 198 

humors of, 193, 194 

interior of, 193, 194, 197 



Eye, lens of, 193, 194 

muscles of, 195 

nerve of, 193, 194, 196 

nerve-coat of, 193, 194, 196 

parts of, 193 

protections to, 192 

pupil of, 193, 194 

questions on', 201 

resemblance of, to photograph- 
er's camera, 195 

rest for, 198 

sclerotic coat of, 193 

synopsis of, 200 
Eyebrows, 192, 193 
Eyelashes, 192, 193 
Eyelids, 192, 193 
Eye-tooth, 77 
Exercise, 56, 57, 182 

and muscles, 56 

and the circulation, 116 

amount of, 57 

forms of, 57 

immediately after meals, 92 

necessity for, 57 
Expression of the face, effect of 

muscles on, 53 
Expiration, 125, 128, 229 

Face, 16, 17 

bones of, 27, 28 

expressions of, 53 
Fainting, 114, 229 

treatment of, 115 
Fang of tooth, 76, 229 
Farinaceous food, 64, 229 
Far-sightedness, 199, 229 
Fat, 48, 66 

digestion of, 91 

uses of, 49 
Fatty food, 66 
Feet, deformed, 25, 26 



244 



INDEX. 



Femur, 20, 22, 34, 36, 229 
Fermentation, 209, 211, 229 
Fibres, 16, 47, 229 
Fibula, 20, 22, 35, 36, 229 
Filth, results of, 180 
Filters, 71 
Fingers, 18, 35 
bones of, 20, 22 
names of, 18 
Fish, 66 

Fishes, blood of, 102 
Flesh, 47, 229 
Fleshy food, 64, 229 
digestion of, 83, 87, 91 
by stomach, 83 
by intestines, 87 
Fluid, synovial, 43 
Fluids of the eye, 193, 194 
Fly-trap, Venus', 14 
Food and drink, 63 
essential to life, 63 
questions on, 72 
synopsis of, 71 
Food and oyxgen produce heat and 

work, 144, 145 
Food of plants, 64 

and animals, difference in, 64 
Food, different kinds of, required 
by man, 64, 66 
easily digested, 84 
farinaceous, 64 
fatty, 49, 66, 87 

digestion of, 91 
fatty, digestion of, in small in- 
testine, 87 
fleshy, 64 
digestion of, 83, 87, 91 
digestion of, in small intestine, 
87 
heavy, 84 
indigestible, 84 



Food, light, 84 

passage for, 129, 130, 186 

proper, 68 

results of combustion of, 144, 
145 

some of simplest forms of, 66 

starchy, 64 
digestion of, 79, 87, 91 
digestion of, in small intestine, 
87 

sugary, 66 

variety in, 68 

vegetable, 64 
Foot, 17, 18, 26 

arch of, 17, 18, 22 

bones of, 20,22,35, 36 

instep of, 17, 18 

sole of, 17, 18 
Forearm, 17, 18 

bones of, 20, 22, 34 
Forehead, 17, 22 
Fracture of bones, 25, 26, 229 
Frontal bone, 22, 27, 29, 229 
Fuel, results of burning of, 144 
Function, 15, 154, 229 

Gall, 89, 229 
Gall-bladder, 75, 88, 89 

canal from, 87 
Gas, carbonic acid, 103 
Gastric juice, 82, 230 

function of, 83 
Gastric tubules, 82, 83 
Gelatin, 24, 230 
Gin, 211 
Glands, 78, 230 

lachrymal, 197 

parotid, 78 

salivary, 78 

sublingual, 79 

submaxillary, 79 



INDEX. 



245 



Glands, tear, 197 
Gliding-joints, 43 
Globules, blood, 100, 101 
Gout, 90, 230 
Granular lids, 199, 230 
Green vegetables, 66 
Gristle, 25, 43, 46, 187, 230 
Groin, 17, 18, 230 
Gullet, 75, 79, 80, 129, 230 
Gum-chewing, 79, 92 
effects of, 79, 92 

Habit, alcohol, 215 

chloral, 217 

cocaine, 218 

morphine, 216 

opium, 216 
Habits which are injurious to di- 
gestion, 92 
Hair, 179 

care of, 183 

color of, 180 

parts of, 179 

root of, 179 
Hammer, 203 
Hand, 18, 20, 22, 35 
Hangnails, 183, 230 
Harvey, 108 
Head, 16, 17 

bones of, 27 

cold in, 188 
Hearing, manner of, 205 

nerve of, 204 

questions on, 207 

sense of, 206 

synopsis of, 206 
Heart, 106, 107, 109 

auricles of, 108 

beats of, 108 

cavities of, 107 

effects of alcohol on, 116 



Heart, effects of tobacco on, 117 

form of, 107 

function of, 108 

palpitation of, 117 

situation of, 106 

valves of, 111, 112 

ventricles of, 108 
Heart and blood-vessels, 100, 106 

questions on, 122 

synopsis of, 119 
Heart-beats, frequency of, 108 
Heat and work, the result of food 

and oxygen, 145 
Heat, blood, 146 

of skin, 146 

of the body, 143, 146 
in sickness, 147 
regulation of, 147, 176, 178 
regulation of, by the skin, 148, 
176, 178 

questions on, 151 

synopsis of, 150 
Heavy food, 84 
Heel, 17, 22, 36 
Hemispheres of cerebrum, 161, 

230 
Hemorrhage, 116, 230 
Herbivorous animals, 64, 230 
Hinge-joints, 43 
Hip, 17, 18, 230 
Hip-bones, 20, 22, 30, 32 
Hip-joint, 22 
Hops, 211, 230 
Humerus, 20, 22, 34, 230 
Humor, aqueous, 193, 194, 230 

vitreous, 193, 194 
Humors of the eye, 193, 194 
Hygiene, 13, 230 

Ice- water, 92, 149 
Images, 196 



246 



INDEX. 



Important muscles, 55 
Impure air, effects of, 135 
Incisor teeth, 77, 230 
Index-finger, 18, 22, 231 
Indigestible food, 84, 231 
Indigestion, 78, 92, 231 
Injurious habits to digestion, 92 
Insensible perspiration, 178 
Inspiration, 125, 127, 231 
Inspired air, course of, 125, 231 
Instep of foot, 17, 18, 36, 231 
Intellect, 163 
Intelligence, 163, 231 
Internal ear, 204 
Intestines, 75, 85, 231 

attachments of, 85 

coats of, 85 

large, 75, 85 

motions of, 86 

projections from inner surface 
of, 86, 87 

small, 75, 85 

openings into, 87 

subdivisions of, 85 

work of, 86, 145 
Intoxication, 212, 215, 231 
Introduction, 13 

questions on, 19 

synopsis of, 18 
Involuntary muscles, 50, 231 
Involuntary nature of breathing, 

133 
Iris, 193, 194, 231 

Jaundice, 89, 231 
Jaw, lower, 22, 29, 30- 

upper, 22, 29, 30 
Joints, 41,42,43, 44, 231 

accidents to, 44 

ball-and-socket, 44 

classes of, 41 



Joints, gliding, 43 

hinge, 43 

immovable, 41, 42 

movable, 41, 42, 43 

pivot, 44 

questions on, 45 

slightly movable, 41, 42 

synopsis of, 45 

varieties of, 43 
Judgment, 163, 261 
Juice, gastric, 82 
function of, 83 

pancreatic, 90 

Kidneys, 145, 231 
Knee, 17, 18 
Knee-pan, 20, 22, 35, 36 

Lachrymal bone, 29, 231 

duct, 197, 198, 231 

gland, 197, 231 
Lacteals, 91, 118, 119, 232 
Lambdoid suture, 42, 232 
Large intestine, 75, 85 
Larynx, 125, 126, 132, 232 

form of, 125 

parts of, 125 

situation of, 125 
Lashes, 192, 193 
Laudanum, 216 
Lead in drinking-water, 71 
Leaf, skeleton of, 155 
Lean, 48, 232 
Leg, 17, 18 

Leg, bones of, 20, 22, 35, 36 
Lens of the eye, 193, 194, 232 
Lens, 192, 193 

granular, 199 
Ligaments, 43, 46, 232 

capsular, 43 
Light food, 84 



INDEX. 



247 



Light in reading, 198 
Limbs, 18, 232 

lower, 18 

upper, 18 
Liquors, 211, 232 
Little finger, 18, 232 
Liver, 75, 88 

cells, 89 

drunkard's, 90 

lobes of, 89 

unhealthy, 90 

uses of, 89 

and gall-bladder, canal from, 87 
Living beings, 14 
Lobes of the liver, 89 
Lower jaw, 22, 29, 30 
Lungs, 130, 132, 145, 149, 232 

circulation through, 109, 110 

effects of tobacco on, 138 

shape of, 130 

structure, 131 
Lymph, 117, 118, 232 
Lymphatics, 117, 118, 232 

Malar bone, 22, 29, 30, 232 

Malt, 211, 232 

Marrow, 24, 232 

Meat, 64, 66 

Medulla, 160, 161, 162, 164, 232 

Membrane, mucous, 81 

synovial, 43 
Membranes of brain, 158 
Membranes of spinal cord, 165 
Memory, 163 

Metacarpus, 20, 22, 35, 233 
Metatarsus, 20, 22, 36, 233 
Methods of cooking, 68 
Microscope, 101, 233 
Middle ear, 202 
Middle finger, 18, 233 
Milk, 67, 91 



Milk, appearance of, under the 
microscope, 67 

composition of, 67 

skimmed, 68 

source of, 67 

teeth, 74 
Mind, 163 
Mixed muscles, 50 . 
Moisture, effects upon heat, 149 
Molar teeth, 77, 233 
Morphine, 216, 233 

habit, 216 
Motion, nerves of, 166 
Mouth, 74, 75 
Mouth-breathing, 133 
Mucus, 82, 233 

Mucous membrane, 81, 86,-233 
Multiple stomachs in some ani- 
mals, 84 
Muscles, 46, 233 

action of, 51 

and exercise, 56 

belly of, 48 

biceps, 51, 53, 54, 55 

care of, 56 

chest, 55 

contraction of, 51 

effect of alcohol on, 57 

effect of tobacco on, 57 

exercise of, 56 

functions of, 47 

groups of, 53 

importance of, 55 

influence of nervous system on 
action of, 52 

number of, 54 

of eye, 194 

of face, 53 

paralyzed, 53 

pectoralis, 54, 55 

questions on, 61 



248 



INDEX. 



Muscles, shape of, 54 

size of, 55 

synopsis of, 59 

temporal, 55 

triceps, 53, 55 
Muscle-fibres, 47, 86 
Muscle-tendons, 48 
Muscle-tissue, 47, 82, 190 

involuntary, 50 

kinds of, 49 

mixed, 50 

voluntary, 49 
Muscular movements, complex, 53 
Mute, deaf-, 205 

Nails, 180 

care of, 183 
Narcotics, 208, 215, 233 
Nasal, 233 

bone, 22, 29, 30 

duct, 197, 198 
Near-sightedness, 199, 233 
Neck, 16, 20, 22 
Neck of tooth, 76 
Nerves, 52, 153, 157, 162, 166, 233 

cranial, 162, 165 

kinds of, 166 

of eyes, 193, 196 

of hearing, 204 

of motion, 166 

of sensation, 166 

of smell, 187, 188 

optic, 193, 196 

spinal, 164, 165 

sympathetic, 169 
Nervous system, 153, 154, 164 

absence of, in plants, 155 

actions of, 157 

divisions of, 156, 164 

effects of alcohol on, 168 

effects of coffee on, 169 



Nervous system, effects of tea on, 
169 

effects of tobacco on, 169 

functions of, 156 

most perfect in man, 156 

questions on, 173 

rapidity of action of, 158 

sympathetic, 169 

synopsis of, 170 
Nervousness, 1G8 
Nitrogen, 102, 233 
Nose, 175, 186 

bone of, 22, 187 

bridge of, 17, 187 

function of, 186 

parts of, 187 

questions on, 190 

synopsis of, 190 
Nostrils, 187, 233 

Occipital bone, 27, 29, 234 

Occiput, 20, 22, 234 

Oculist, 196, 234 

(Esophagus, 75, 79, 80, 129, 234 

Oil-tubes, 179 

Old-sight, 200 

Openings into small intestine, 87 

Opium, 216, 234 

habit, 216 
Optic, 234 

Optic nerve, 193, 196 
Orbits, 30, 192, 234 
Organ, 15, 234 
Outer ear, 202 
Oxygen, 102, 110, 134, 135, 145, 234 

Palm op hand, 18, 35 
Palpitation of heart, 117, 219 
Pancreas, 75, 90, 234 

canal from, 88 
Pancreatic juice, 90 



INDEX. 



249 



Pancreatic juice, uses of, 91 
Paralysis, 234 
Paralyzed muscles, 53, 234 
Parietal bone, 27, 29, 234 

suture, 42 
Parotid gland, 78, 234 
Passage for air, 129, 130 

for food, 129, 130 
Patella, 20, 22, 35, 36, 234 
Pectoralis muscle, 54, 55, 234 
Pelvis, 22, 32, 234 
Pepsin, 83, 234 
Perfume, 189 
Pericardium, 107, 235 
Periosteum, 24, 235 
Peritoneum, 81, 86, 235 
Permanent teeth, 75 
Perspiration, 149, 178, 235 

insensible, 178 

sensible, 178 

uses of, 179 
Perspiration tubes, 178 
Phalanges, 20, 22, 35, 36, 235 
Pharynx, 75, 235 
Physiology, 13, 235 
Pivot-joints, 44 

Plants, absence of nervous system 
in, 155 

food of, 64 

life in, 14 

life and growth of, 135 
Plants and animals, difference be- 
tween, 15, 135 

difference in the food of, 15, 64, 
135 

similarity in structure of, 154 
Plasma of the blood, 100, 102, 235 

uses of, 103 
Pleura, 133, 145, 235 
Pores, 145, 149, 181, 235 
Porter, 211 



Projections on inner surface of 

small intestine, 86, 87 
Proper food, 68 
Protection of windpipe, 127 
Pulmonary artery, 109, 235 
Pulp of tooth, 76, 235 
Pulse, 113 

Pupil of eye, 193, 194, 235 
Purification of the air, 135 

of blood, 110 

of drinking-water, 70 
Pylorus, 75, 80, 85, 235 

Radius, 20, 22, 34, 235 
Reading, precautions in, 198, 199 
Reason, 163, 235 
Red blood-globules, 101 

use of, 102 
Reflex action, 166, 235 
Refuse materials, 144, 145 
Reptiles, blood of, 102 
Respiration, 125, 235 
Retina, 193, 194, 196, 236 
Ribs, 22, 30, 33, 236 
Ring finger, 18, 236 
Root of hair, 179 

of tooth, 76 
Rum, 211 
Russian baths, 182 

Sacrum, 20 

Sagittal suture, 42, 236 

Saliva, 78, 190, 236 

uses of, 79 
Salivary glands, 78, 236 
Sap, 155 
Scalp, 17, 236 
Scapula, 20, 22, 32, 236 
Scarf-skin, 177, 236 
Scents, sweet, 189, 236 
Sclerotic coat of the eye, 193, 236 



250 



INDEX. 



Sensation, organ of, 173, 286 

nerves of, 166, 176 
Senses, 175, 236 

special, 175 
Sense of hearing, 175, 202 

of sight, 175, 192 

of smell, 175, 183 

of taste, 175, 190 

of touch, 175 
Sensible perspiration, 149, 178 
Serum of blood, 104 
Shoes, improper, £5, 26 
Shoulder, 17, 18 

Shoulder-blade, 20, 22, 30, 32, 34 
Sight, old, 200 

organ of, 192 

sense of, 175, 192 
questions on, 201 
synopsis of, 200 

weak, 199 
Skeleton, 20, 21,22,47,236 

care of, 25 

front view of, 20 

of leaf, 155 

parts of, 27 

position of, 21 

questions on, 39 

side view of, 22 

synopsis of, 37 
Skimmed milk, 68 
Skin, 175 

a means of regulating the body- 
heat, 149, 176, 178 

as the organ of sensation, 175 

attachments of, 178 

care of, 180 

color of, 177 

heat of, 146 

necessity for, 175 

questions on, 185 

scarf, 177 



Skin, structure of, 177 

synopsis of, 184 

thickness of, 175 

throwing off water, salts, and 
poisonous matters, 145, 176 

true, 177 

uses of, 145, 149, 175 
Skull, 27, 28, 236 

bones of, 29 
Sleep, 167 

amount of, 167 

children's, 167 

uses of, 167 

time for, 167 
Sleeplessness, 168 
Small intestine, 75, 85 
Smell, nerves of, 187, 188 

sense of, 175, 186 
in lower animals, 187 
questions on, 190 
synopsis of, 189 
uses of, 188 
Smelling and breathing channels, 

186 
Smoker's sore-throat, 188, 219 
Sole of foot, 17, 18, 36, 236 
Sound, 128, 204 
Sounds, production of, 128, 204 
Spaces, air, 132 
Speaking, 129, 191 
Special senses, 175, 236 
Sphenoid bone, 29 
Spinal, 236 

canal, 31 

column, 22, 30, 31 

cord, 31, 157,164, 165 

nerves, 164, 165 
Spine, 31 
Spirit, 208 
Spleen, 75, 93, 237 
Squint, 195, 237 



INDEX. 



251 



Starch, 64, 65, 237 

digestion of, 79, 87, 91 
Starchy food, 64 

digestion of, 79, 87, 91 
Sternum, 20, 22, 32, 34, 237 
Stimulant, 66, 208, 237 
Stimulants and narcotics, 208 

questions on, 223 

synopsis of, 219 
Stirrup, 203 
Stomach, 75, 80, 81, 237 

discovery of mode of action of, 
84 

effects of alcohol on, 84 

effects of tobacco on, 84 

form of, 75, 80 

multiple in some animals, 84 

openings in, 80 

structure of, 80, 81 

uses of, 83 
Stout, 211 

Sublingual gland, 79, 237 
Submaxillary gland, 79, 237 
Sugar, 65 
Sugary food, 65 
Summer, keeping cool in, 148 
Sunstroke, 149 
Suture, coronal, 42, 237 

lambdoid, 42 

parietal, 42 

sagittal, 42 
Sutures, 41, 42 
Sweetbread, 90 
Sweet scents, 189 

Sympathetic system of nerves, 169 
Synovial fluid, 43, 237 

membrane, 43 
System, 155, 237 

Tarsus, 20, 22, 36, 237 
Taste, sense of, 175, 190 



Taste, abuse of, 191 

questions on, 192 

synopsis of, 192 
Tea, 66, 169, 208 
Tear-duct, 197, 198 
Tear-gland, 197 
Tear-sac, 197, 198 
Tears, 197 
Teeth, 74, 70, 77 

bicuspid, 77 

canine, 77 

care of, 78 

crown of, 76, 77 

fang of, 76, 77 

incisor, 77 

milk, 74 

molar, 77 

names of, 77 

neck of, 76, 77 

number of, 74, 75 

parts of, 76, 77 

permanent, 75, 77 

root of, 76, 77 

structure of, 76 

temporary, 74 . 

uses of, 77 

wisdom, 76 
Temple, 28, 237 
Temporal bone, 28, 29, 237 

muscle, 55 
Temporary teeth, 74 
Tendon of Achilles, 56, 237 
Tendons, 48 
Thermometer, 146, 237 
Thigh, 17, 18, 237 
Thigh-bone, 20, 22, 35, 36 
Thorax, 18, 20, 22, 33, 237 
Thought, 163 
Throat, 74, 79 

communication with the middle 
ear, 203 



252 



INDEX. 



Throat, effects of tobacco on, 188 

Thumb, 182, 237 

Tibia, 20, 22, 35, 36, 238 

Tight clothing, effects of, on 

breathing, 25, 138 
Tissues, 15, 238 
Tobacco, 117 
effects on circulation, 117 
on digestion, 93, 219 
on heart, 117, 219 
on lungs, 138 
on muscles, 57 
on nervous system, 169, 219 
on skeleton, 27 
on stomach, 84, 219 
on system, 218 
on throat, 138 
Tobacco heart, 117, 219 
Toes, bones of, 20, 22, 36 
Tongue, 80, 175, 190, 191 
questions on, 192 
structure of, 190 
synopsis of, 192 
uses of, 190 
Tonics, 211 
Touch, organ of, 175 
sense of, 175 

questions on, 185 
synopsis of, 184 
Trachea, 125, 126, 129, 132, 238 
Training, 58, 213, 238 

of brain, 163 
Triceps muscle, 53, 55, 238 
True skin, 177 
Trunk, 18, 238 
bones of, 30 
cavities of, 18 
Tube, bronchial, 126, 130, 132 

Eustachian, 204 
Tubes, oil, 179 
perspiration, 178 



Tubule, 82, 238 
Tubules, gastric, 82, 83 
Turkish baths, 182 

Ulna, 20, 22, 34, 238 
Uncleanliness, results of, 180 
Upper jaw, 22, 29, 30 

Valve, 111, 238 
Valves of heart, 111, 112 

of veins, 114 
Vegetable food, 64, 66, 238 
Vegetables, green, 66 
Veins, 99, 112, 113, 238 

valves of, 114 
Ventilation, 135, 238 
Ventricles of heart, 108, 238 
Venus' fly-trap, 14 
Vertebra?, 31, 238 

union of, 31 
Vesicles, air, 132 
Vinegar, 210 
Vinous fermentation, 210 
Vitreous, 193, 194, 238 

humor of eye, 193, 194 
Vocal cords, 127, 128, ]29, 238 
Voice, production of, 128 

organ of, questions on, 141 
synopsis of, 139 
Voluntary muscles, 49, 238 

Wakefulness, 168 
Warm-blooded animals, 146 
Warmth in winter, 148 
Water, 66, 69 

ice-, 92, 149 

drinking-, 69 

of rivers, 70 
Wax of ear, 202, 206 
Weak-si arht, 199 



INDEX. 



253 



Whiskey, 211 

White blood -globules, 101 

White of eye, 193 

Will, 163 

Wines, 211 

Windpipe, 125, 126, 129, 130, 238 

branches of, 126, 130, 132 

form of, 129, 132 

protection of, 127 

rings of, 126, 130, 132 



Windpipe, situation of, 129 

Winter, keeping warm in, 148 

Wisdom-tooth, 76 

Woollen clothing, 147 

Work and heat the results of food 

and oxygen, 144, 145 
Wort, 211 
Wrist, 18, 20, 22, 35 

Yeast, 67, 211, 238 



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